Disentangling bias: national capabilities,regime type,and international conflict mediation

Abstract

Existing literature on bias and third-party conflict management mainly focuses on the dichotomy of whether the mediator’s bias as a whole can contribute to mediation onset and outcomes. I argue that we need more specific and disaggregated research on the mediator’s bias because the side on which a prospective mediator’s bias lies may significantly affect the likelihood of mediation onset. Why are some biased mediations initiated by third parties while others are not? By disentangling the mediator’s bias and by distinguishing between different levels of bias, I find that the likelihood of mediation onset tends to increase if the potential mediator shares a closer political relationship with a conflicting state that has greater national capabilities or that is more authoritarian than the counterparty. However, the effect is largely conditional on the levels of the mediator’s bias, where a more obvious level of bias is more likely to facilitate mediation initiation. This article advances our understanding of bias and international conflict mediation.

Keywords

Bias international conflict mediation national capabilities political relationship regime type

Introduction

The frequency of contentions between states and the frequency of third-party conflict management have shown an increasing trend since the end of the Second World War.¹ In recent decades, the field of international conflict mediation has emphasized the study of bias, that is, the differences in the relationships between a mediator and each of two conflicting parties.² Existing literature on bias and third-party conflict management has focused on the dichotomy of whether the mediator’s bias as a whole can positively affect mediation as well as the mechanisms underlying the mediator’s bias (e.g. Carnevale and Arad, 1996; Carnevale and Pruitt, 1992; Maoz and Terris, 2006; Rauchhaus, 2006; Regan, 2002; Savun, 2008; Svensson, 2009). However, by narrowly focusing on whether a mediator has a closer political, economic or social relationship with a particular party to a conflict, previous literature on bias and third-party conflict management has largely overlooked more specific and disaggregated research on the mediator’s bias.

Why are some biased mediations initiated by third parties while others are not? Under what specific circumstances is bias more likely to affect the likelihood of international conflict mediation? Thus far, our understandings of these important questions have been inadequate. Therefore, it is helpful for scholars to investigate the incidence of mediation initiation by more closely scrutinizing the mediator’s bias. Arguably, third parties are more likely to mediate conflicts that are more difficult to resolve bilaterally by the two parties and that will lead to deadly combat (Bercovitch and Jackson, 2001). Therefore, when a conflict is rather difficult to resolve, the likelihood of mediation initiation increases if the mediator’s bias can ameliorate the atmosphere and mitigate the problems involved in the conflict, which in turn will contribute to the settling of international conflicts. Because the difficulty of settling an interstate conflict is largely dependent on influencing factors with regard to the two conflicting states, this study intends to disentangle the characteristics of the party toward which the potential mediator holds bias.

Using data on all prospective mediators within 173 bilateral disputes with 316 mediations in the Western Hemisphere and Western Europe from 1946 to 2000, this article makes two key contributions to the research on bias and international conflict mediation.³ First, unlike most previous literature that explores the effect of bias as a whole on mediation, I more closely examine the characteristics of the conflicting state with whom the potential mediator shares a closer political relationship, which may ultimately determine the likelihood of mediation initiation. Although existing research has made meaningful attempts to study civil war mediation (e.g. Svensson, 2007), to the best of my knowledge, this article is the first attempt to investigate the precise conditions under which biased mediation is more likely to take place within interstate conflict. Second, most of previous literature methodologically treats the mediator’s bias as a simple dummy that indicates whether the mediator is biased toward either side of the conflict or uses the absolute value of the difference in the relationships between a mediator and each of two conflicting parties. In contrast, to more appropriately measure bias and to have a better understanding of the impact of bias on mediation initiation, I further distinguish between different levels of the mediator’s bias. In summary, this article supports previous literature (e.g. Favretto, 2009; Kydd, 2003; Melin, 2011; Savun, 2008; Smith 1985) that argues that bias is able to contribute to international mediation by providing specific conditions under which bias is more likely to facilitate mediation initiation.

The remainder of this article is organized as follows. The second section reviews the related literature on bias, the characteristics of the conflicting states and the initiation of mediation. Then, it puts forward the main hypotheses of this research. The third section lays out the details of the research design, including a new distinction between different levels of bias. The fourth section then presents the empirical results, which are consistent with the hypotheses. The last section concludes the article and discusses future avenues for the research on how bias may affect international conflict mediation.

Disentangling bias: theories and hypotheses

There is an enduring academic debate on the role of bias in third-party conflict management. Several scholars suggest that an unbiased mediator is more appealing to conflicting parties and, thus, is more likely to be accepted (e.g. Rauchhaus, 2006; Svensson, 2009). Carnevale and Pruitt (1992) argue that unbiased mediation is more likely to bring disputants to the table because the mediator is considered fair and is therefore trusted by the conflicting parties. Conversely, Bercovitch (1996) is suspicious of the role of bias because it is the resources and ability of mediators to affect a change rather than the appearance of impartiality that contributes to the effectiveness of mediation (cf. Bercovitch and Schneider, 2000).

Kydd (2003) argues that a biased mediator has an advantage in credibly signaling information to its favored party, whereas an unbiased mediator who is more interested in minimizing the possibility of conflict has a stronger incentive to provide information, even if it is not true.⁴ Thus, biased mediation can be and often is more effective; this conclusion is consistent with some previous literature (e.g. Carnevale and Arad, 1996; Regan, 2002; Smith, 1985; Touval, 1982) and more recent research also provides additional support for this argument (e.g. Favretto, 2009; Maoz and Terris, 2006; Melin, 2011, 2015; Savun, 2008). Building on Kydd’s (2003) model, Crescenzi et al. (2011) consider bias to be only a complementary source of credibility and provide several mechanisms for unbiased mediators to become credible and successful mediators as well.

Existing studies have yielded extensive knowledge and understanding on bias and mediation from various perspectives. Nevertheless, previous literature uses different definitions of mediation and its success, different operationalizations of bias, different sources of data and different empirical methods.⁵Savun (2008) argues that, “while the proponents of impartiality perceive a mediator’s impartiality as a main source of its influence, the proponents of bias similarly contend that bias is a main source of a mediator’s influence as well.”⁶ Consequently, no scholarly consensus has been reached on whether or how the mediator’s bias influences international conflict mediation.

Much of previous quantitative research examines the influence of bias on interstate conflict mediation based on either whether a mediation attempt is biased or the extent to which the mediator’s relationships with each of two conflicting parties differ (e.g. Crescenzi et al., 2011; Gent and Shannon, 2011; Rauchhaus, 2006; Savun, 2008). However, I argue that considerable important information and knowledge may be concealed when bias is aggregated by simply treating it as a dummy variable or by using the absolute value of the difference in the mediator’s relationships with each of two conflicting parties. Thus, more specific research on the mediator’s bias is worthwhile because the side with which a prospective mediator shares a closer relationship may significantly affect the likelihood of mediation onset.

On this issue, some more qualitatively oriented literature provides valuable insights. This research suggests that bias is expected to contribute to the extraction of concessions from the party toward which the mediator is biased. When the mediator has a closer relationship with a particular side of a conflict, a possible reason for the opposing party to accept the offer of mediation may be that it expects that the mediator will convince its opponent to offer concessions (Stephens, 1988). Carnevale and Arad (1996) argue that a biased mediator can benefit from a “cushioning effect.” Based on the logic of the effect of bias on the mediator’s credibility, a biased mediator is more likely to convince its favored parties to make the necessary concessions because a mediator who seeks to extract concessions from a party must convince the party that the mediator has its interests at heart. Analogously, Touval (1982) and Zartman (1995) demonstrate that biased mediation can be advantageous because the mediator can pressure and force the party with which it shares a closer relationship to make concessions.

If this result commonly occurs, however, why do many biased mediations fail to be initiated? Under what circumstances is a party’s concession forced by a third party more likely to affect the initiation of mediation? When is a disfavored party more likely to accept the mediator? Past studies have not yet provided convincing or specific answers to these questions. In a study on civil war mediation, Svensson (2007) theoretically and empirically distinguishes between whether the mediator is biased toward the insurgency movement and toward the incumbents. He suggests that we must account for the asymmetry between rebels and governments in the stage of conflict negotiation. Analogously, in interstate conflict mediation, asymmetry between two conflicting states with regard to national capabilities and regime type often exists. Therefore, we should also examine the precise conditions under which biased mediators can be effective peacemakers (Wallensteen and Svensson, 2014), which demands a more disaggregated theoretical and empirical analysis that is focused on how the characteristics of the party toward which a potential mediator is biased may affect the possibility of initiating interstate conflict mediation.

National capabilities, bias, and mediation initiation

The parties to a conflict evaluate the costs of continuing the conflict when they consider whether to accept a mediator (Greig and Regan, 2008). Conflicting parties calculate the costs and benefits of mediation, and they will accept mediation only if they expect initiating mediation to generate a more favorable outcome than continuing the conflict (Wilkenfeld et al., 2003). Because the status quo is more likely to disadvantage the weaker party to the conflict, the weaker side has a strong motivation vis-à-vis the stronger side to accept mediation and a cease-fire in order to avoid greater potential losses. Accordingly, whether mediation is initiated is largely contingent upon the stronger party to the conflict. Thus, a weaker party that is more eager to achieve a truce must accept a mediator who does not share a closer relationship with it in order to secure a relatively better solution if the weaker side is unable to find a potential mediator who can both support it and be accepted by the opposing party to the conflict.

In an uneven match, there is a certain likelihood that the weaker party is threatened by the power of the stronger party to the conflict. Kressel and Pruitt (1989) argue that mediators who intend to improve the atmosphere between the parties to a conflict are the clearest embodiment of the traditional view that mediators are catalysts and facilitators rather than arm-twisters or proponents of a particular solution. With respect to intrastate conflict, because governments have incentives to eliminate rebel leaders when conflicts end, third parties’ commitments for peace agreements may allay the weaker side’s fear and consequently increase the chances of a peaceful settlement (Mitchell, 2016). Svensson (2007) argues that a potential mediator who is biased toward the government may remedy the rebels’ commitment problem when they need to negotiate and agree to terminate their violent behavior because the rebel side sends a costly signal of conciliatory intention by accepting a government-biased mediator, whereas a mediator who is biased toward the rebels may have fewer incentives to protect the government if the rebels renege on a peace deal. Similarly, in interstate conflict mediation, a biased mediator is able to mitigate the fear of the opposing side and the consequent commitment problems derived from the power disparity. A weaker state understands that to extricate itself from the commitment problem, it has to accept a mediator who is biased toward the counterparty. By accepting a mediator who is biased toward the counterparty, the weaker state then shows its trustworthiness and sincerity with respect to the resolution of the dispute.

Additionally, mediation is more likely to be effective when the capabilities of both parties to a conflict are evenly matched because it is more difficult for a stronger party to make the concessions and compromises that are essential to mediation success (Bercovitch and Houston, 2000). A biased mediator may have special leverage and add credibility to the party with which the mediator shares a closer relationship (Carnevale and Arad, 1996; Kydd, 2003, 2006; Stephens, 1988; Touval, 1982). From this perspective, the mediator’s influence will be more significant if the prospective mediator is biased toward the side of the conflict that would otherwise be less willing to make the necessary concessions to the opposing party. When a party to a conflict surpasses its opposing party in national capabilities, a biased mediator who has the leverage and credibility of the stronger side can be considered likely to extract concessions from the party with which it shares a closer relationship, which, in turn, can increase the likelihood of initiating mediation.

Notwithstanding the asymmetry in national capabilities, the stronger party to the conflict is aware that continuing the conflict is not the purpose, particularly in the modern era; rather, a mediation attempt meets its eventual need. When a mediator has closer political connections with the stronger side, that party is cognizant that the mediator has its interests at heart, and hence, offering necessary concessions is regarded as reasonable. Otherwise, if the prospective mediator is biased toward the weaker party to the conflict, the stronger party is not willing to accept the mediator, let alone make concessions, since the expected outcome of the conflict management is less likely to benefit it.

A good example is Algeria’s mediation of the Iranian Hostage Crisis (Slim, 1992). In September 1980, the Iranians released a message indicating that they were ready to settle the dispute, which was regarded as Iran’s new attitude of offering concessions. At that time, there were only a few states with which both Iran and the United States had working relationships and which they could both agree would be an acceptable intermediary (Allouche, 1987). The Iranians were aware that the relationship between the United States and Syria or Libya was far from friendly, and Algeria seemed to be the most likely of the three potential mediators to be accepted by the United States. Thus, although Iran was on better terms with Syria and Libya, Iran actually had no other option but to request the help of Algeria in settling the dispute. Therefore, I put forward the first hypothesis of this research below.

Hypothesis 1. Mediation is more likely to be initiated if the potential mediator has a closer relationship with the party to the conflict that has greater national capabilities than the counterparty.

Regime type, bias, and mediation initiation

Numerous democratic peace studies suggest that peaceful conflict settlements are more likely to occur between democratic states than between non-democratic pairs because democracies are more open to peaceful conflict management techniques (Dixon, 1994; Mousseau, 1998). Because shared norms and sociopolitical similarities can minimize misperceptions and facilitate the successful conclusion of a conflict, a non-democratic state may have difficulties interacting with democratic states (Bercovitch and Houston, 2000).

Scholars acknowledge that more democratic states are, in general, more amenable to the efforts of third parties to resolve or ameliorate interstate conflicts than states that are more authoritarian, partly because of the norm of compromise, which is a central and defining feature of democratic political culture (Mousseau, 1998). States that are more democratic are generally more likely to adopt compromise solutions to international problems (Dixon, 1994), and it is reasonable to expect that compared with a more authoritarian state, a relatively more democratic (or less authoritarian) state will be more willing to make concessions and to accept third-party conflict management efforts even if the mediator is biased toward the opposing side. Thus, for the parties to a conflict, it is reasonable to argue that the willingness to make necessary concessions and accept mediation corresponds to the degree of democracy and reversely corresponds to the degree of authoritarianism.

Meanwhile, a mediator who has a closer relationship with the more authoritarian state is able to serve as a type of information transmitter between the two belligerents. In comparison with states that are less authoritarian, states that are more authoritarian face fewer costs for sending false information because their deceptive behavior is less likely to be uncovered in the process of public scrutiny (Crescenzi et al., 2011). A potential mediator who shows bias toward the more authoritarian party has more channels to access information regarding that party’s intentions and capabilities, which may otherwise be difficult to access. Mediators who have relevant information about both parties to a conflict tend to be more successful than those without such information (Savun, 2008). Relevant information concerning both parties to a conflict is essential for a prospective mediator to implement strategies and techniques to bring both disputants to the table. A prospective mediator who has a closer political relationship with the more authoritarian party is more capable of obtaining relatively equivalent information from both conflicting states, which contributes to a higher possibility that the less authoritarian party will accept the mediation. As a mediator’s degree of information about the conflicting parties’ military capabilities and their willingness to fight increases, the likelihood of a peaceful settlement also increases (Savun, 2008).

Adopting a minimalist approach to democracy and transparency, Hollyer et al. (2011) observe that there is a significant relationship between regime type and the willingness of policy-makers to provide credible announcements on policy-relevant information. Scholars contend that because of the transparency of their institutions, more democratic states have greater credibility in their foreign policy behavior and higher audience costs for foreign policy than states that are less democratic (Fearon, 1994). Further, the behavior of a more democratic state is more predictable than that of a more authoritarian state when addressing interstate conflict. Therefore, another reason why a conflicting state is willing to accept a potential mediator whose bias lies with the more authoritarian party is that the prospective mediator is expected to apply some pressure or constraint on the party that is more authoritarian, which thereby promotes mediation initiation.

Specific support for this contention is provided by the cases of the Korean Peninsula Crisis and the North Korean Nuclear Crisis. In April 1996, North Korea unilaterally announced that it had abandoned a cease-fire agreement and sent military forces into the demilitarized zones. South Korea and the United States put forward a proposal to invite China to join the peacemaking mechanism in order to access China’s connections with North Korea and to prevent North Korea from escalating the dispute. Likewise, China played an essential and crucial role in initiating the Six-Party Talks on the Korean Nuclear Issue beginning in 2003 (Rozman, 2007; Teng, 2008). Both the United States and South Korea were well aware that China had a close political relationship with North Korea and that only China would be able to persuade North Korea to settle this crisis. The United States insisted on avoiding negotiating with North Korea bilaterally and agreed to contact North Korea only with China serving as an intermediary. Additionally, in the Mayaguez incident between the United States and Cambodia, the United States also requested the help of a Chinese liaison to demand the release of crew members from Cambodia (Bercovitch and Jackson, 1997).⁷ Thus, I specify my second main hypothesis as follows.

Hypothesis 2. Mediation is more likely to be initiated if the potential mediator has a closer relationship with the party to the conflict that is more authoritarian than the counterparty.

Research design

Data and sample selection

To examine when mediation is more likely to be initiated with regard to the national capabilities and regime type of the conflicting states, we must obtain the following information: (a) what the conflict per se concerned and which two conflicting states were involved in the conflict; (b) whether a third party mediated the conflict; and (c) what state(s) was/were selected to mediate. Version 1.1 of the Issues Correlates of War (ICOW) dataset, which provides systematic data on explicit contentions between nation-state actors, is suitable for the purposes of this research (Hensel, 2001; Hensel et al., 2008).⁸

The ICOW dataset contains three types of issues, that is, territorial claims, river claims, and maritime claims. The project has collected comprehensive data for all three types of issues in the Western Hemisphere and Western Europe.⁹ Thus, scholars are more confident about the data for these regions than for other areas because the data regarding other regions may be influenced by omitted issues or regional data availability.¹⁰ Therefore, the empirical analysis of this study is focused primarily on the Western Hemisphere and Western Europe.¹¹ Although the geographical scope of this article is limited, the focus on the Western Hemisphere and Western Europe ameliorates the problem with omitted variable bias because these regions share greater internal political and cultural similarities.¹² Moreover, this research is still able to offer important insights for international mediation in other parts of the world.¹³

In the stage of mediation initiation, Beardsley (2011) suggests that the following three conditions must be met: (a) the conflicting parties must agree to work with a mediator; (b) the conflicting parties must find a mutually acceptable third party; and (c) the third parties must be willing to become involved in the conflict. Melin et al. (2013) observe that the circumstances that attract potential mediators are not exactly the same as those that make mediation desirable to conflicting states. Conversely, the characteristics that make third parties more forthcoming with mediation offers simultaneously make conflicting states more likely to reject mediation proposals.

The ICOW project systematically records dyadic disagreements and contentions in world politics, some of which have been mediated. Therefore, we have access to the information concerning (a) which conflicts were mediated by which particular third parties as well as (b) which conflicts were not mediated by any third party. However, prospective mediations that were (a) invited by the combatants but rejected by the potential third parties or (b) offered by the prospective third parties but declined by either or both of the conflicting parties remain undetermined. To make an appropriate evaluation of the incidence of mediation, we need a comprehensive pool of states as the potential mediators for each observation that takes into account the cases where potential mediation services were not rendered (not recorded in the ICOW dataset).

Consistent with Crescenzi et al. (2011) and Melin et al. (2013), I consider all prospective state mediators and use a prospective state mediator for each year of a dyadic claim as the unit of analysis. Based on the original ICOW dataset, which has dyad-year data regarding the three types of issues (territory, river, and maritime), I include every potential state mediator in each ongoing dyad-year of each claim.¹⁴ More specifically, for a conflict that was not mediated by any state, all prospective mediators comprise the pool. For a conflict that was mediated by state(s), every potential mediator besides the “actual” mediator is considered. By taking advantage of this strategy, I am able to eliminate the selection effects associated with not including the unobservable cases (Melin et al., 2013) and to examine the individual characteristic of each potential mediator’s bias, which provides the most direct test of the hypotheses (Crescenzi et al., 2011).

The set of prospective mediators includes (a) all states in the same region of the dispute and (b) the major powers in the international system defined by the Correlates of War (COW) Major Power dataset (Correlates of War Project, 2011; Small and Singer, 1982). Through this strategy of extended case selection, there are 97,812 total observations, including 86,803 observations concerning the Western Hemisphere and 11,009 cases concerning Western Europe.¹⁵ The data in this research covers 173 bilateral contentions with 316 mediations during the period from 1946 to 2000.¹⁶

Measuring bias

Carnevale and Arad (1996) contend that there are two major forms of bias in mediation: (a) bias of content, which pertains to mediator behavior (e.g. one side is favored in a mediator’s settlement proposal); and (b) bias of source characteristic, which pertains to expectations that originate from the mediator’s closer personal, political, or economic ties to one of the parties.¹⁷ However, bias of content in mediation is difficult to perceive and analyze because no scholars have access to information regarding how a mediator originally designed a settlement or any unofficial settlements of a conflict. Therefore, I define bias as the mediator’s closer political ties and similar foreign policy preferences to one side of a conflict.

In line with numerous previous studies (e.g. Crescenzi et al., 2011; Favretto, 2009; Gent, 2007; Gent and Shannon, 2011), I measure bias based on the S-score of a state’s alliance portfolios. The pattern of alliances among states reflects the extent to which the states have common or conflicting interests in international security issues (Signorino and Ritter, 1999). The S-score ranges from −1 to 1, where higher S-scores between states indicate more similar foreign policy preferences.

Unlike most previous studies that use only one measurement of bias, that is, either a dummy variable indicating whether a mediator shows bias toward a particular side of a conflict or the absolute value of the difference in the relationships between a mediator and each of two conflicting parties, this article considers different levels of the mediator’s bias. Admittedly, mediators have their own incentives and interests that motivate their willingness to offer mediation services (Findley and Marineau, 2015). In most cases, the mediator’s interest in resolving a conflict originates from its relationship with one or both conflicting parties. Since mediation services have costs, a mediator is more willing to bear these costs if it has a greater proximity to disputants (Corbetta, 2015). However, prospective mediators’ interests toward two conflicting parties are always unbalanced (Smith, 1985).

The data of this article provides specific support for this argument (see Figure 1). Overall, regarding the global similarity scores, more than 60% (60,801 of 97,812) of the potential mediators share closer relationships with either party to a conflict. Moreover, a certain proportion of potential mediators show only a moderate level of bias toward a particular party to a conflict. I argue that if the difference in bias toward two conflicting states is too small, there is arguably a certain likelihood that it would be difficult for both prospective mediators and the conflicting parties to perceive the difference. This difficulty may, in turn, be insufficient to create variation in the considerations regarding whether mediation services can be promised. Therefore, to establish a more proper measurement of bias and to obtain a better understanding of the impact of bias on mediation initiation, I distinguish between different levels of the mediator’s bias and use a sensitivity analysis to check the statistical results in later sections.

Figure 1.

Distribution of the levels of the mediator’s bias.

Variables and operationalization

The primary research question of this article is how the side on which the mediator’s bias lies affects the likelihood of the initiation of mediation. Thus, the dependent variable is whether mediation is initiated. Mediation is a dummy variable that is coded 1 if mediation is initiated and is coded 0 otherwise. Previous sections of this article have discussed whether a prospective mediator shows bias toward a party that has greater national capabilities and that is more authoritarian than the counterparty. Therefore, there are two main independent variables, greater capabilities bias and more authoritarian bias, and both are binary dummy variables.

Greater capabilities bias: The Composite Index of National Capability (CINC), which ranges from 0 to 1, measures states’ average share of global military, economic, and demographic power in each year, and it is therefore a proper indicator of states’ national capabilities (Singer et al., 1972). The variable greater capabilities bias is coded 1 if the alliance portfolio similarity score between a prospective mediator and the conflicting state with the higher CINC score is greater than the score between the prospective mediator and the conflicting state with the lower CINC score,¹⁸ and it is coded 0 otherwise.

More authoritarian bias: The difference in regime type between two conflicting parties is measured using the Polity 2 scores of the Polity IV project dataset (Marshall and Jaggers, 2002), which captures the regime type of states in the world and ranges from −10 to 10, where a higher score indicates a relatively more democratic state and a lower score indicates a relatively more authoritarian state. The variable more authoritarian bias is coded 1 if the alliance portfolio similarity score between a prospective mediator and the conflicting state with the lower Polity 2 score is greater than the alliance portfolio similarities between the prospective mediator and the conflicting state with the higher Polity 2 score,¹⁹ and it is coded 0 otherwise.

Because mediation efforts are not randomly selected, several scholars have addressed the selection effects in international conflict mediation (e.g. Beber, 2012; Greig and Regan, 2008; Melin et al., 2013; Melin and Svensson, 2009). Greig (2005) suggests that mediation efforts are driven by a combination of forces, including the stalemate of the contention, the characteristics of the belligerents, the conflict management history, and the presence of an ongoing militarized dispute; none of these factors is able to provide a complete picture of mediation initiation individually. To further understand the relationships between the independent and dependent variables in this research, I introduce several control variables that may generally affect the likelihood of mediation initiation.

Major powers are more actively involved than other countries throughout the world; thus, mediation is largely restricted to the great powers (Bercovitch and Schneider, 2000). A peaceful settlement is likely when a highly biased major power intervenes in a conflict because the conflicting parties are certain that the mediator will enforce an agreement through military means (Favretto, 2009). Additionally, the international community puts more pressure on major powers to perform their duties and fulfill their obligations (Savun, 2008). Thus, the first control variable is the mediator’s capabilities, which is measured using the CINC scores (Singer et al., 1972).²⁰ It is also predicted that the democratic level of the potential mediators may influence mediation initiation because a more democratic state is arguably more likely to make peaceful settlement attempts (Crescenzi et al., 2011; Kadera et al., 2003). Here, I use the Polity 2 scores of the Polity IV project to capture the mediator’s democracy (Marshall and Jaggers, 2002).

The way in which issues are perceived by conflicting parties affects the probability that a successful or unsuccessful mediation outcome is achieved because the severity of a conflict depends upon how intensely the parties value the issue (Bercovitch and Houston, 2000). There is a consensus among mediation scholars that mediation attempts are more likely to occur with higher intensity conflicts (Greig, 2005). Thus, I utilize the issue salience index from the ICOW dataset, which captures the importance of the claimed territory, river, or maritime zone to the two parties to a conflict based on factors such as resources, strategic location, homeland, and historical sovereignty. This index indicates the importance and nature of the conflict, and higher values signify greater salience (Hensel et al., 2008).

I also control for the parties’ past experiences in the conflict because previous experiences affect states’ subsequent choices concerning peaceful conflict resolution methods (Diehl and Regan, 2015; Wiegand and Powell, 2011). It is expected that recent Militarized Interstate Disputes (MIDs) will increase conflicting parties’ willingness to make necessary concessions and agree to initiate mediation (Ghosn et al., 2004; Jones et al., 1996). Recent successful peaceful settlement attempts may also increase the likelihood of new mediation initiation. Following the ICOW project (Hensel, 2001; Hensel et al., 2008), I use the number of recent MIDs between the conflicting parties and the number of recent successes regarding these disputes, which are weighted by recency.²¹ Finally, the identity of the conflict is considered. Territorial claim and river claim are two dummy variables that indicate whether the conflict pertains to a territorial or river issue.²² In summary, Table 1 presents the descriptive statistics for all of the independent and control variables in the models.

Table 1.

Descriptive statistics of the independent and control variables

Variables	Observations	Mean	SD	Minimum	Maximum
Independent variables
Greater capabilities bias	97,812	0.1905	0.3927	0	1
More authoritarian bias	91,172	0.3218	0.4672	0	1
Control variables
Mediator’s capabilities	97,812	0.0200	0.0458	0.0000	0.3640
Mediator’s democracy	97,812	2.3449	7.2197	−10	10
Issue salience	97,812	6.5501	2.1062	0	12
Recent MIDs	97,812	0.1740	0.5026	0	4.6
Recent successes	97,812	0.3422	0.8298	0	9
Territorial claim	97,812	0.3434	0.4749	0	1
River claim	97,812	0.0589	0.2354	0	1

Empirical results

After reviewing existing literature, advancing the main hypotheses, and introducing the data and methods used in this study, I then present and discuss the empirical results in this section. Because the dependent variable in this study is a dummy variable that indicates whether mediation is initiated, binary logit regressions are suitable to analyze the empirical data. However, through the strategy of sample extension, the incidence of mediation in this study is rather low (316 of 97,812 cases, corresponding to <1%). King and Zeng (2001) argue that the conventional logistic regressions may underestimate the probability of rare events. Thus, I utilize the rare events logistic regressions, which correct existing methods and change the estimates of absolute and relative risks.²³ Since not every case is independent of other cases, robust standard errors that adjust for clustering on claim participants are generated to account for the possible correlation across the observations.

Table 2 reports the results of the rare events logistic regressions on mediation initiation. Model 1 includes the two core independent variables, greater capabilities bias and more authoritarian bias, whereas other variables are not controlled for. The control variables are included in Model 2.²⁴Table 2 shows that neither of the independent variables (greater capabilities bias and more authoritarian bias) has a significant impact on the probability of mediation initiation in Model 1. Although more authoritarian bias becomes significant (p≤ 1%) in Model 2, where all the control variables are included, we cannot contend with confidence that the side toward which the mediator is biased can significantly affect the likelihood of mediation initiation.

Table 2.

Rare events logistic regressions of bias on mediation initiation

	Model 1	Model 2
Independent variables
Greater capabilities bias	0.369 (0.561)	0.652 (0.472)
More authoritarian bias	0.505 (0.463)	0.900 (0.296)**
Control variables
Mediator’s capabilities		11.531 (2.116)***
Mediator’s democracy		0.055 (0.016)***
Issue salience		0.128 (0.076)^†
Recent MIDs		0.854 (0.230)***
Recent successes		0.264 (0.080)***
Territorial claim		0.042 (0.591)
River claim		–0.211 (0.917)
Constant	–5.980 (0.347)***	–8.250 (0.624)***
Observations	91,172	91,172

Note: Robust standard errors clustered by claim participants are in parentheses. ^†p⩽ 10%, **p⩽ 1%, ***p⩽ 0.1%, in a two-tailed test.

In the previous parts of this article (and in almost all existing literature), the two independent variables are operationalized based on whether the potential mediator has a closer political relationship with either belligerent. Nonetheless, as is illustrated in Figure 1 and in the previous sections, treating all levels of the mediator’s bias as homogeneous is not a proper way to examine the effect of bias on mediation. Are the empirical results in Table 2 applicable to all levels of the mediator’s bias? Do the levels of the mediator’s bias make a difference? To gain a better understanding of the impact of bias on mediation initiation, I use a sensitivity analysis of different levels of bias to check the statistical results. I report the results of the sensitivity checks in Table 3, where all control variables, constants, and numbers of observations are omitted for the sake of brevity.

Table 3.

Sensitivity analysis of different levels of bias

Excluded level	Building on Model 1		Building on Model 2
Excluded level	Capabilities bias	Authoritarian bias	Capabilities bias	Authoritarian bias
bias < 0.1	0.240	0.417	0.506	0.807**
	(0.574)	(0.447)	(0.470)	(0.275)
bias < 0.2	0.260	0.107	0.565	0.541*
	(0.613)	(0.367)	(0.541)	(0.261)
bias < 0.3	0.541	0.381	0.635	0.730*
	(0.497)	(0.339)	(0.506)	(0.306)
bias < 0.4	1.364**	0.259	1.508**	0.609*
	(0.522)	(0.306)	(0.488)	(0.239)
bias < 0.5	2.159***	0.439	2.181***	0.676^†
	(0.492)	(0.396)	(0.512)	(0.356)
bias < 0.6	3.202***	1.031*	3.705***	1.860***
	(0.590)	(0.469)	(0.533)	(0.420)
bias < 0.7	3.959***	1.504**	4.190***	2.219***
	(0.618)	(0.477)	(0.537)	(0.353)
bias < 0.8	3.216***	1.569***	3.727***	2.219***
	(0.875)	(0.448)	(0.590)	(0.303)

Note: This table reports the coefficients and robust standard errors (in parentheses), clustered by claim participants, regarding the two independent variables of the rare events logistic regressions on mediation initiation when utilizing different coding procedures of bias. All control variables, constants, and numbers of observations are omitted. ^†p⩽ 10%,*p⩽ 5%, **p⩽ 1%, ***p⩽ 0.1%, in a two-tailed test.

Building on Models 1 and 2, I gradually exclude lower levels of the mediator’s bias. In Table 2, greater capabilities bias and more authoritarian bias are coded based on whether the potential mediator shares different S-scores with the two combatants.²⁵ In Table 3, however, I utilize different coding procedures of bias. For instance, the first row of Table 3 reports the statistical results concerning the two independent variables where greater capabilities bias is coded 1 if the S-score between the prospective mediator and the conflicting state with the higher CINC score is greater by at least 0.1 than the S-score between the prospective mediator and the conflicting state with the lower CINC score,²⁶ and it is coded 0 otherwise. More authoritarian bias is coded 1 if the S-score between the potential mediator and the conflicting state with the lower Polity 2 score is greater by at least 0.1 than the S-score between the prospective mediator and the conflicting state with the greater Polity 2 score,²⁷ and it is coded 0 otherwise.²⁸ Likewise, the second row of Table 3 shows the statistical results with regard to the two independent variables where the difference in S-score is greater by at least 0.2,²⁹ the third row of Table 3 reports the results with regard to the independent variables where the difference in S-score is greater by at least 0.3,³⁰ and so forth.

Interestingly, as is indicated in Table 3, the effect of bias on mediation initiation varies as the level of the prospective mediator’s bias changes. Greater capabilities bias generates no significant impact on the initiation of mediation when the bias is smaller than 0.3, but the significance becomes stronger as the level of bias increases. In a similar way, more authoritarian bias, in general, yields a more significant influence on mediation initiation when lower levels of bias are excluded from the coding procedure. Thus, I confirm that the probability of initiating a mediation can significantly increase if the potential mediator has a closer political connection with the party to the conflict that has greater national capabilities or that is more authoritarian than the opposing party. These results suggest that the side toward which the mediator is biased is able to significantly affect the likelihood of mediation initiation, even though several control variables are taken into account. Furthermore, the effect is not homogeneous but is conditional on the levels of the mediator’s bias; different levels of bias have different impacts on mediation initiation. In general, compared with a more moderate (or a less obvious) level of bias, a more obvious level of bias is more likely to facilitate mediation initiation.

Regarding the control variables, the mediator’s capabilities, the mediator’s democracy, recent MIDs, and recent successes are significant in Model 2 of Table 2 (p≤ 1%). Therefore, the possibility of initiating mediation tends to increase when the prospective mediator has greater national capabilities or when the prospective mediator’s level of democracy increases. The possibility of initiating mediation also increases when more recent MIDs between the parties to a conflict have occurred or when the disputes between the two parties have been recently successfully settled through peaceful techniques. The identity of the conflict (i.e. territorial claim and river claim), however, does not significantly influence mediation onset.

Conclusion

Numerous studies on bias and international conflict mediation have generated disparate outcomes regarding whether and how the mediator’s bias facilitates the initiation of mediation and improves mediation performance. Nonetheless, our knowledge on bias and mediation is still insufficient in terms of the specific conditions under which the mediator’s bias is more likely to contribute to mediation. Therefore, I suggest that research on bias and third-party conflict management should move beyond simply examining whether and how bias as a whole can facilitate mediation and that we demand more disaggregated research on bias.

By disentangling the potential mediator’s bias, I provide a fresh perspective regarding when biased mediators can be more beneficial to mediation initiation. I examine the incidence of mediation initiation among all prospective mediators based on the ICOW project dataset. The main conclusion of this research is that the likelihood of the initiation of interstate conflict mediation can increase if the potential mediator shares a closer political relationship with the conflicting state that has greater national capabilities or that is more authoritarian than the counterparty. Notably, the levels of bias condition the effect of bias on mediation initiation. By distinguishing between different levels of bias, I examine the effect of different levels of bias on mediation initiation. The empirical results of the sensitivity analysis indicate that not all levels of bias have the same impact on interstate conflict mediation onset. Rather, excluding lower levels of bias generates more significant results. These findings suggest that the effect of bias on mediation initiation is largely conditioned by the levels of bias, where the mediator’s bias is more likely to make a difference if the bias is more obvious. Since most previous literature fails to distinguish between different levels of bias that may generate different outcomes concerning international conflict mediation, this article provides important insights regarding why there may be no scholarly consensus on the role of the mediator’s bias. Therefore, scholars should be aware that it is necessary to take into account the distinction between different levels of bias.

The findings of this article shed important light on future avenues for academic research on bias and international conflict mediation. Admittedly, by including all potential mediators for each dispute dyad based on the ICOW dataset, this study examines mainly the effect of the side on which each potential mediator’s bias lies on the likelihood of mediation initiation, which inevitably overlooks the circumstances of multiparty mediation (Böhmelt, 2011). In multiparty mediation, how does the potential mediator’s bias toward the conflicting parties combine with that of other mediators? How can the conclusions of this article be applied to cases of multiparty mediation? In addition, the interrelationships among multiparty mediators will influence the effectiveness of mediation. How do the potential mediator’s political connections with other prospective mediators affect the likelihood of initiating mediation? These research questions require further investigation.

This article concludes that mediation is more likely to be initiated if the potential mediator has a closer political relationship with the stronger or the more authoritarian party and that this effect is conditional on the levels of bias. Furthermore, what happens if the mediator is biased toward the party that is both stronger and more authoritarian than the counterparty? Interestingly, I find no mediation initiation if the potential mediator’s bias lies on the side that is both stronger and more authoritarian. On the one hand, since there is a strong negative correlation between a state’s national capabilities and its level of authoritarianism (p≤ 0.1%), the number of observations in which the potential mediator is biased toward the party with both characteristics is extraordinarily small (approximately only 1% of all cases). On the other hand, the ICOW dataset indicates that every dispute in the period from 1946 to 2000 is settled bilaterally if one belligerent is both greater in national capabilities and more authoritarian than the opposing side. A more comprehensive understanding of why the combatants choose this type of conflict settlement but not others (e.g. negotiation, mediation, or arbitration) will be meaningful.

Meanwhile, given the criteria in this article, I only consider state actors as potential mediators. International organizations (whether global or regional) and all other actors are therefore inevitably ignored. In reality, international organizations play an important and active role and have a unique influence on international security and peace (Gartner, 2011; Lundgren, 2016; Pevehouse and Russett, 2006; Shannon, 2009). Moreover, international organizations can also be engaged in managing and resolving conflicts along with states. Thus, we require more specific research that aims at analyzing how international organizations’ bias affects mediation onset and outcomes.³¹

Footnotes

Acknowledgements

For helpful inputs, I would like to thank Mark J.C. Crescenzi, Allan Dafoe, Ji-Young Ko, Andrew H. Kydd, Mathilda Lindgren, Ming Lu, Jon C.W. Pevehouse, Haixia Qi, Yu-Sung Su, Henrik Urdal, Yizhou Wang, Jessica Chen Weiss, Jian Xu, and Jiahua Yue. I am indebted to the three anonymous reviewers and the editor of Conflict Management and Peace Science for their insightful comments and excellent suggestions. Any and all possible errors are of course my own.

Author’s note

Previous versions of this article were presented at the 2015 annual meeting of the Midwest Political Science Association in Chicago, the 2015 annual meeting of the Chinese Community of Political Science and International Studies in Beijing, and at a workshop at Fudan University. The data and all other supporting materials of this article can be accessed via a supplementary data file hosted on SAGE’s CMPS website.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Notes

References

Allouche

(1987) Small States and International Mediation: The Case of Algeria. College Park, MD: University of Maryland Press.

Beardsley

(2011) The Mediation Dilemma. Ithaca, NY: Cornell University Press.

Beber

(2012) International mediation, selection effects, and the question of bias. Conflict Management and Peace Science29(4): 397–424.

Bercovitch

(1996) Introduction: Thinking about mediation. In: Bercovitch

(ed.) Resolving International Conflicts: The Theory and Practice of Mediation. Boulder, CO: Lynne Rienner.

Bercovitch

Houston

(2000) Why do they do it like this? An analysis of the factors influencing mediation behavior in international conflicts. Journal of Conflict Resolution44(2): 170–202.

Bercovitch

Jackson

(1997) International Conflict: A Chronological Encyclopedia of Conflicts and Their Management 1945–1995. Washington, DC: Congressional Quarterly Inc.

Bercovitch

Jackson

(2001) Negotiation or mediation? An exploration of factors affecting the choice of conflict management in international conflict. Negotiation Journal17(1): 59–77.

Bercovitch

Schneider

(2000) Who mediates? The political economy of international conflict management. Journal of Peace Research37(2): 145–165.

Böhmelt

(2011) Disaggregating mediations: The impact of multiparty mediation. British Journal of Political Science41(4): 859–881.

10.

Carnevale

Arad

(1996) Bias and impartiality in international mediation. In: Bercovitch

(ed.) Resolving International Conflicts: The Theory and Practice of Mediation. Boulder, CO: Lynne Reinner.

11.

Carnevale

Pruitt

(1992). Negotiation and mediation. Annual Review of Psychology43: 531–582.

12.

Clarke

(2005) The phantom menace: Omitted variable bias in econometric research. Conflict Management and Peace Science22(4): 341–352.

13.

Clarke

(2009) Return of the phantom menace: Omitted variable bias in econometric research. Conflict Management and Peace Science26(1): 46–66.

14.

Corbetta

(2015) Between indifference and coercion: Third-party intervention techniques in ongoing disputes. Conflict Management and Peace Science32(1): 3–27.

15.

Correlates of War Project (2011) State system membership list, v. 2011. Available from: http://correlatesofwar.org (accessed 23 October 2014).

16.

Crescenzi

MJC

Kadera

Mitchell

Thyne

(2011) A supply side theory of mediation. International Studies Quarterly55(4): 1069–1094.

17.

Diehl

Regan

(2015) The interdependence of conflict management attempts. Conflict Management and Peace Science32(1) 99–107.

18.

Dixon

(1994) Democracy and the peaceful settlement of international conflict. American Political Science Review88(1): 14–32.

19.

Favretto

(2009) Should peacemakers take sides? Major power mediation, coercion, and bias. American Political Science Review103(2): 248–263.

20.

Fearon

(1994) Domestic political audiences and the escalation of international disputes. American Political Science Review88(3): 577–592.

21.

Findley

Marineau

(2015) Lootable resources and third-party intervention into civil wars. Conflict Management and Peace Science32(5): 465–486.

22.

Gartner

(2011) Signs of trouble: Regional organization mediation and civil war agreement durability. The Journal of Politics73(2): 380–390.

23.

Gartner

Premack

(2014) Mitigating conflicts of interest in regional governmental organization civil war mediation. Wisconsin International Law Journal31(4): 785–817.

24.

Gent

(2007) Strange bedfellows: The strategic dynamics of major power military interventions. The Journal of Politics69(4): 1089–1102.

25.

Gent

Shannon

(2011) Bias and the effectiveness of third-party conflict management mechanisms. Conflict Management and Peace Science28(2): 124–144.

26.

Ghosn

Palmer

Bremer

(2004) The MID 3 dataset, 1993–2001: Procedures, coding rules, and description. Conflict Management and Peace Science21(2): 133–154.

27.

Greig

(2005) Stepping into the fray: When do mediators mediate?American Journal of Political Science49(2): 249–266.

28.

Greig

Regan

(2008) When do they say yes? An analysis of the willingness to offer and accept mediation in civil wars. International Studies Quarterly52(4): 759–781.

29.

Hensel

(2001) Contentious issues and world politics: The management of territorial claims in the Americas, 1816–1992. International Studies Quarterly45(1): 81–109.

30.

Hensel

Mitchell

Sowers

Thyne

(2008) Bones of contention: Comparing territorial, maritime, and river issues. Journal of Conflict Resolution52(1): 117–143.

31.

Hollyer

Rosendorff

Vreeland

(2011) Democracy and transparency. The Journal of Politics73(4): 1191–1205.

32.

Jones

Bremer

Singer

(1996) Militarized interstate disputes, 1816–1992: Rationale, coding rules, and empirical patterns. Conflict Management and Peace Science15(2):163–213.

33.

Kadera

Crescenzi

MJC

Shannon

(2003) Democratic survival, peace, and war in the international system. American Journal of Political Science47(2): 234–247.

34.

King

Zeng

(2001) Logistic regression in rare events data. Political Analysis9(2): 137–163.

35.

Kressel

Pruitt

(1989) Conclusion: A research perspective on the mediation of social conflict. In: Kressel

Pruitt

(eds) Mediation Research: The Process and Effectiveness of Third-Party Intervention. San Francisco, CA: Jossey Bass.

36.

Kydd

(2003) Which side are you on? Bias, credibility, and mediation. American Journal of Political Science47(4): 597–611.

37.

Kydd

(2006) When can mediators build trust?American Political Science Review100(3): 449–462.

38.

Lundgren

(2016) Conflict management capabilities of peace-brokering international organizations, 1945–2010: A new dataset. Conflict Management and Peace Science33(2): 198–223.

39.

Lundgren

Svensson

(2014) Leanings and dealings: Exploring bias and trade leverage in civil war mediation by international organizations. International Negotiation19(2): 315–342.

40.

Maoz

Terris

(2006) Credibility and strategy in international mediation. International Interactions32(4): 409–440.

41.

Marshall

Jaggers

(2002) Polity IV Project: Data set User’s Manual. College Park, MD: University of Maryland Press.

42.

Melin

(2011) The impact of state relationships on if, when, and how conflict management occurs. International Studies Quarterly55(3): 691–715.

43.

Melin

(2015) Escalation in international conflict management: A foreign policy perspective. Conflict Management and Peace Science32(1): 28–49.

44.

Melin

Svensson

(2009) Incentives for talking: Accepting mediation in international and civil wars. International Interactions35(3):249–271.

45.

Melin

Gartner

Bercovitch

(2013) Fear of rejection: The puzzle of unaccepted mediation offers in international conflict. Conflict Management and Peace Science30(4): 354–368.

46.

Mitchell

(2016) Dangerous bargains with the devil? Incorporating new approaches in peace science for the study of war. Conflict Management and Peace Science. First Published 29 September 2016; doi: 10.1177/0738894216667621.

47.

Mousseau

(1998) Democracy and compromise in militarized interstate conflicts, 1816–1992. Journal of Conflict Resolution42(2): 210–230.

48.

Pevehouse

Russett

(2006) Democratic international governmental organizations promote peace. International Organization60(4): 969–1000.

49.

Rauchhaus

(2006) Asymmetric information, mediation and conflict management. World Politics58(2): 207–241.

50.

Regan

(2002) Third-party interventions and the duration of interstate conflicts. Journal of Conflict Resolution46(1): 55–73.

51.

Rozman

(2007) Strategic Thinking about the Korean Nuclear Crisis: Four Parties Caught between North Korea and the United States. New York: Palgrave Macmillan.

52.

Savun

(2008) Information, bias, and mediation success. International Studies Quarterly52(1): 25–47.

53.

Shannon

(2009) Preventing war and providing the peace? International organizations and the management of territorial disputes. Conflict Management and Peace Science26(2): 144–163.

54.

Signorino

Ritter

(1999) Tau-b or not tau-b: Measuring the similarity of foreign policy positions. International Studies Quarterly43(1): 115–144.

55.

Singer

Bremer

Stuckey

(1972) Capability distribution, uncertainty, and major power war, 1820–1965. In: Russett

(ed.) Peace, War, and Numbers. Beverly Hills, CA: Sage.

56.

Slim

(1992) Small-state mediation in international relations: The Algerian mediation of the Iranian Hostage Crisis. In: Bercovitch

Rubin

(eds) Mediation in International Relations: Multiple Approaches to Conflict Management. New York: St Martin’s Press.

57.

Small

Singer

(1982) Resort to Arms: International and Civil Wars, 1816–1980. Beverly Hills, CA: Sage.

58.

Smith

(1985) Effectiveness of the biased mediator. Negotiation Journal1(4): 363–372.

59.

Stephens

(1988) Acceptance of mediation initiatives: A preliminary framework. In: Mitchell

Webb

(eds) New Approaches to International Mediation. Westport, CT: Greenwood Press.

60.

Svensson

(2007) Bargaining, bias and peace brokers: How rebels commit to peace. Journal of Peace Research44(2): 177–194.

61.

Svensson

(2009) Who brings which peace? Neutral versus biased mediation and institutional peace arrangements in civil wars. Journal of Conflict Resolution53(3): 446–469.

62.

Svensson

(2015) International Mediation Bias and Peacemaking: Taking Sides in Civil Wars. London: Routledge.

63.

Teng

(2008) Conflict management in East Asia: The China–Taiwan–North Korea conundrum. In: Bercovitch

Huang

Teng

(eds) Conflict Management, Security, and Intervention in East Asia: Third-party Management in Regional Conflict. New York: Routledge.

64.

Touval

(1982) The Peace Brokers: Mediators in the Arab–Israeli Conflict, 1948–1979. Princeton, NJ: Princeton University Press.

65.

Wallensteen

Svensson

(2014) Talking peace: International mediation in armed conflicts. Journal of Peace Research51(2): 315–327.

66.

Wiegand

Powell

(2011) Past experience, quest for the best forum, and peaceful attempts to resolve territorial disputes. Journal of Conflict Resolution55(1): 33–59.

67.

Wilkenfeld

Young

Asal

Quinn

(2003) Mediating international crises: Cross-national and experimental perspectives. Journal of Conflict Resolution47(3): 279–301.

68.

Zartman

(1995) Dynamics and constraints in negotiations in internal conflicts. In: Zartman

(ed.) Elusive Peace: Negotiating An End to Civil Wars. Washington, DC: Brookings Institution Press.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

1.48 MB

0.00 MB