Abstract
As online reviews have become increasingly prevalent in recent years and their influence on consumers’ purchasing decisions has grown exponentially, some companies have begun to ask people to write fake reviews about their businesses or their competitors while offering compensation in return. This process has drawn the attention of regulators because it knowingly misleads consumers. This article reports on two studies that looked at the effect of two types of incentives (self-benefiting or charitable) on individuals’ intentions to write fake reviews and examined the moderating role of a person’s sense of power on his or her propensity to post a fake review. The study findings indicate that powerless individuals are more likely to post a fake review when presented with a monetary incentive rather than a charity incentive, while powerful individuals are not impacted by incentive type. Moreover, when asked to post negative fake reviews about competitors, such effects are mitigated.
Introduction
Word of mouth (WOM) has a huge impact on consumer behavior (Berger 2014; Chevalier and Mayzlin 2006; Trusov, Bucklin, and Pauwels 2009) and online reviews, a form of electronic word of mouth (eWOM), are widely recognized as the most impactful information source in consumers’ decision-making processes (Hennig-Thurau et al. 2004; Gruen, Osmonbekov, and Czaplewski 2006; Park and Lee 2009). Consumers trust other consumers’ recommendations of a product more than company-generated communications (Hennig-Thurau and Walsh 2003).
Hospitality and travel services tend to be intangible and experience-based and their attributes cannot be completely assessed until they have been purchased and consumed (Zeithaml, Bitner, and Gremler 2012). Consumers of such services tend to rely on recommendations from others in order to minimize uncertainty and perceived risk (Murray 1991) and the most recent and most widely used version of those recommendations is the online review (e.g., Ring, Tkaczynski, and Dolnicar 2016).
Previous research has examined the impact of online reviews on trip planning (Gretzel and Yoo 2008), hotel performance (Phillips et al. 2015; Ye, Law, and Gu 2009), hotels’ responses to online reviews (Sparks, So, and Bradley 2016; Wei, Miao, and Huang 2013), and consumers’ motivations to read or post online reviews (Bronner and de Hoog 2011; Kim, Mattila, and Baloglu 2011; Wu et al. 2016). More recently, there has been a focus on the effects of various central cues (Filieri and McLeay 2014) as well as peripheral cues in online reviews on consumers’ decision-making processes, such as review valence (Sparks and Browning 2011), reviewer’s expertise (Vermeulen and Seegers 2009; Zhang, Zhang, and Yang 2016), reviewer’s identity (Liu and Park 2015; Xie et al. 2011), and source credibility (Ayeh, Au, and Law 2013; Zhang, Wu, and Mattila 2014).
There is growing evidence to suggest that both businesses and consumers generate fake reviews, a practice that undermines the credibility of the process (Mayzlin, Dover, and Chevalier 2014; Simonson 2016). For instance, a hotel located nearby a competitor tends to have more fake, negative reviews than a hotel with no close competitors (Mayzlin, Dover, and Chevalier 2014). This phenomenon is frequently observed in the restaurant context as well (Luca and Zervas 2015).
The occurrence of fake online reviews has begun to receive attention, both from the media and state and federal regulators. The Federal Trade Commission (FTC) recently introduced endorsement guidelines, stating that “if there is a connection between an endorser and the marketer that consumers would not expect and it would affect how consumers evaluate the endorsement,” an endorser should disclose that connection clearly (FTC 2015, 2). Yet, while fake reviews are investigated at various levels, there is scant research on consumers’ motivation to engage in such reviews. To fill this gap, this study examines whether different types of incentives (i.e., self-benefiting vs. other-benefiting) influence consumers’ propensity to write fake reviews. Being compensated for writing a fake online review creates a moral dilemma. People can choose to be unethical and post a fake review in order to support a charity. Or, they can be unethical and post a fake review to receive some benefits for themselves. Finally, people might choose to be ethical and not post a fake review.
This study examines the role of a person’s sense of power in this dilemma and we propose that an individual’s sense of power, the capacity to control resources or outcomes in social relationships (Keltner, Gruenfeld, and Anderson 2003), influences a person’s response to an unethical request. Although common sense dictates that people can be motivated by something that benefits them personally, this study demonstrates that individuals are also motivated by incentives that benefit others, depending on their personal sense of power. Whereas powerless individuals tend to activate a concrete mindset and focus on self-interests, powerful individuals typically activate an abstract mindset and prioritize a greater social good (Rixom and Mishra 2014). Based on a review of the relevant literature on unethical behaviors, incentives, and sense of power, this study explores the ethical issues associated with posting fake online reviews. Specifically, we examine the joint effects of power and incentive type on consumers’ propensity to post either positive or negative fake reviews.
Literature Review
Unethical Behaviors and Fake Online Reviews
Writing a fake review is unethical and “illegal or morally unacceptable to the large community” (Jones 1991, 367). Research in social psychology and marketing has touched upon a variety of unethical behaviors, such as individuals’ propensity to engage in lying (Fischbacher and Föllmi-Heusi 2013), stealing and cheating (Yap et al. 2013), and other unethical behaviors (Vitell 2003). Yet, as consumer behavior is no longer confined to traditional personal interactions, researchers have begun to investigate unethical behaviors in online settings such as software piracy (Chiou, Wan, and Wan 2012) and retailers falsifying product information (Lu, Chang, and Yu 2013).
Hancock (2007, 290) describes “digital deception” as the “intentional control of information in a technologically mediated message to create a false belief in the receiver of the message.” He further states that digital deception must be (a) “intentional or deliberate” and (b) “designed to mislead or create a false belief in some target.” Based on this definition, fake online reviews fall into the category of digital deception.
Fake reviews are written to promote a business by unethical means and to deliberately mislead readers in their purchase decisions (Yoo and Gretzel 2009). For example, Harmon (2004) shows that many book reviews on Amazon were written by publishers and the authors themselves. Fake reviews are not only an issue in the retail industry but also in the travel industry. A hotel, for instance, might benefit from deceptively posting positive reviews about its own property and by posting negative reviews about competing properties on TripAdvisor.com (Mayzlin, Dover, and Chevalier 2014; Yoo and Gretzel 2009). However, when Mayzlin (2006) examined whether firms benefit from promotional reviews or chats in online communities, she found that it is not beneficial to produce a high volume of deceptive reviews, since creating and posting such reviews are costly. Moreover, she shows that eWOM remains persuasive despite misrepresentations in promotional reviews.
Previous research has explored the detection of deception in online communities, and studies in computer science and information technology have developed automated identifier systems to filter out fake reviews (Hu et al. 2012; Mukherjee, Liu, and Glance 2012). When comparing fake and actual reviews, Yoo and Gretzel (2009) and Ott et al. (2011) conclude that deceptive and actual, honest reviews are different in terms of their lexical complexity and the use of first-person pronouns. A recent study by Luca and Zervas (2015) uses the fraud filter on Yelp.com to detect fake reviews and found that promotional, fake reviews tend to be more extreme than other reviews.
Recently, researchers have also examined the role of verified reviewers who actually purchased a product or experienced a service (Anderson and Simester 2014). Mayzlin, Dover, and Chevalier (2014) compare hotel ratings on TripAdvisor.com and Expedia.com. Whereas Expedia.com requires the customer posting a review to have had an actual reservation at the hotel, TripAdvisor.com does not, thus creating an environment that might be more conducive to fake reviews. Their study shows that reviews on TripAdvisor.com tend to be more extreme, thus potentially fake.
Whereas several studies have investigated various methods to detect deceptive reviews, to our knowledge, previous research has not examined the reviewer’s motivation to post fake reviews. In this study, we are primarily interested in fake reviews posted by consumers rather than by service providers. We define fake reviews as reviews written by consumers who did not purchase a product or a service and who still wrote a review about it. In the following section, we first discuss the role of incentive types followed by an individual’s sense of power in influencing their propensity to post fake reviews.
Incentives
In this study, we are interested in two types of incentives: self-benefiting (e.g., a discount in future purchases) and other-benefiting (e.g., contribution to charity).
A monetary reward is a powerful tool in motivating people to behave in certain ways. Previous research has demonstrated the importance of monetary (self-benefiting) incentives in enhancing employee motivation (Stajkovic and Luthans 2003), business unit outcomes (Peterson and Luthans 2006), and creative thinking (Eisenberger and Rhoades 2001). Moreover, research in marketing shows that monetary incentives are effective in generating positive WOM (Hennig-Thurau et al. 2004; Jin and Huang 2014; Wirtz and Chew 2002).
The other form of incentive, the charitable contribution, has received less attention. Yet, as corporate social responsibility (CSR) gains prominence in today’s corporate world, this kind of incentive has increasingly been used in cause-related marketing campaigns. For example, marketers often promise to donate a certain amount of an item’s purchase price to a charity. The effects of charity incentives depend on donation framing and on the price of the product (e.g., a bottle of shampoo vs. a color ink-jet printer) (Chang 2008). Strahilevitz and Myers (1998) demonstrate that, as compared to monetary incentives, charity incentives are more effective in promoting hedonic products rather than utilitarian products. Previous studies also suggest that the effect of charity incentives on product choice is moderated by the customers’ involvement in the cause and by customer–corporate identification (e.g., Nicole, Stefan, and Hoyer 2012).
The focus of this study is on examining if, and how, these two types of incentives motivate individuals to post fake reviews. Although monetary incentives can lead to socially responsible behaviors (e.g., Iyer and Kashyap 2007), they may backfire when used as justifications for unethical behaviors. Xie et al. (2014) suggest that when there is a monetary incentive to engage in a moral transgression, ethical dissonance (Barkan et al. 2012) is smaller, thereby enabling people to justify immoral behaviors. In other words, money seems to “share” some of the guilt, thereby diminishing the attribution of unethical behaviors to intrinsic motives (Barkan et al. 2012; Shalvi et al. 2015; Winterich, Mittal, and Morales 2014; Xie et al. 2014).
When charity incentives are used to persuade people to write fake reviews, there is an ethical dilemma: helping others by engaging in unethical behaviors. Such a situation is somewhat different from regular ethical dilemmas, which are defined as “situations in which no moral choice is without undesirable moral consequences” (Ditto and Liu 2012, 55). When a conflict exists between two ethical principles, people negotiate between potential outcomes and decide which one takes priority over the other, thereby influencing their behavior (Rixom and Mishra 2014). However, such prioritizing behaviors may vary depending on an individual’s sense of power (DeCelles et al. 2012; Kraus, Piff, and Keltner 2009), and therefore, we want to examine the moderating role of power in influencing consumers’ propensity to write fake reviews.
Sense of Power
Power refers to asymmetric control over resources or other people in social relationships (Keltner, Gruenfeld, and Anderson 2003). Such resources can be monetary, legitimate authority, or intellectual capital (French and Raven 1959). French and Raven (1959) demonstrate that power can arise from relationships based on five components: coercion, reward, legitimacy, reference, or expertise. Coercive power is the ability to let someone to do something forcibly. Reward power refers to the ability to retain or give something to someone. Legitimate power is the ability to administer to certain feeling of obligation. Finally, expert power stems from holding information that can be shared by others. Depending on the context, power can be generally described as rich vs. poor, boss vs. subordinate, or expert vs. novice. Accordingly, one of the frequently used power manipulations asks participants to imagine themselves as a boss or employee (Dubois, Rucker, and Galinsky 2010; Galinsky, Gruenfeld, and Magee 2003). However, it is important to note that resources are determined by an individuals’ subjective perception of such resources. Consistent with this perspective, previous marketing literature has defined power as perceived asymmetric control over resources in social relations (Rucker, Galinsky, and Dubois 2012) Thus, the present research adapts this notion of power.
The effects of power on human behavior have been extensively studied in the psychology and sociology literature (e.g., Anderson and Berdahl 2002; Galinsky, Gruenfeld, and Magee 2003). Similarly, the role of power on consumer behavior has been investigated in a variety of contexts: power shapes not only consumers’ information processing (e.g., Anderson and Galinsky 2006; Mourali and Nagpal 2013) but also their behaviors (e.g., Garbinsky, Klesse, and Aaker 2014; Rucker, Galinsky, and Dubois 2012).
Anderson and Galinsky (2006) show that high-power individuals are more likely to engage in risky behaviors because of enhanced optimism about risks (e.g., unprotected sex). Mourali and Nagpal (2013) conclude that high-power consumers tend to focus on positive product features and adopt a choosing strategy (i.e., select a preferred option), whereas low-power consumers focus on negative features and adopt a rejecting strategy (i.e., fail to purchase the product or service). Rucker and Galinsky (2009) demonstrate that low-power consumers are more likely to have a strong desire to acquire products (which are associated with status) to compensate for their lack of power, while high-power consumers are not heavily influenced by such a desire. Previous studies in the hospitality and travel literature have shown that power moderates the impact of relationship status (friends or strangers) on customer satisfaction when receiving unearned preferential treatment (Zhang and Hanks 2015), the impact of other customers’ dress styles on the focal customer’s approach behavior (Choi and Mattila 2016), and the impact of experience congruity with other customers on willingness to post online reviews (Wu et al. 2016).
Power, Incentives, and Unethical Behaviors Combined
In this article, we argue that individuals’ reactions to incentives that are related to writing fake reviews vary depending on their sense of power. Past research in social psychology has demonstrated the impact of social class and power on individuals’ propensity to engage in unethical behaviors. Social class and power are conceptually and empirically distinct. However, past research shows that people of higher social class tend to have greater resources, which in turn enhance their sense of power. Therefore, social class and power yield similar effects, such as neuroendocrine changes (e.g., Carney, Cuddy, and Yap 2010) and spending behavior (Piff et al. 2010; Rucker, Dubois, and Galinsky 2011). Scholars have suggested several reasons why high social class and power induce unethical behaviors. The general belief is that, if a person has control over resources (i.e., higher social class and power), she or he is less dependent on others. Thus, the individual feels less pressure to abide by social norms or to act prosocially (Lammers et al. 2015). There is further evidence to suggest people of higher social class engage in unethical behaviors because of greed (Piff et al. 2012), while individuals of lower social class engage in prosocial behaviors because of their concern and compassion for others (Piff et al. 2010). However, another stream of research argues that lower social class individuals are more likely to engage in unethical behaviors than higher social class individuals (e.g., Brush 2007).
Building on this contradiction, Dubois, Rucker, and Galinsky (2015) suggest that the beneficiary of unethical acts influences people’s behaviors. According to the agentic–communal model (Bakan 1966), powerful people tend to foster an agentic orientation, which makes them focus on the self, while powerless people tend to foster a communal orientation, thus leading to focus on others (Rucker, Galinsky, and Dubois 2012). Based on the agentic–communal model of power, Dubois, Rucker, and Galinsky (2015) suggest that people of a higher social class or high power are more likely to engage in unethical behaviors when such an act helps themselves. Conversely, individuals of a lower social class or those who feel powerless are more likely to engage in unethical behaviors when the beneficiary is another person. However, we expect a different pattern of results based on the notion of power–mindset association (Smith and Trope 2006).
Power has also been linked to an individual’s mindset (Rucker, Galinsky, and Dubois 2012). Past research has shown that power might not directly influence an individual’s behavior, but might rather trigger an individual’s underlying traits or mindset (Chen, Lee-Chai, and Bargh 2001; DeCelles et al. 2012). Relying on the construal-level theory (Trope and Liberman 2003), Smith and Trope (2006) argue that any factors that influence an individual’s psychological distance from an object also affect his or her propensity to form an abstract or concrete representation of the object. As such, Smith and Trope (2006) show that high-power people tend to process information in an abstract manner because they are more independent of others, have a greater sense of distinctiveness, and feel more psychologically distant from others (Keltner, Gruenfeld, and Anderson 2003; Lee and Tiedens 2001). In contrast, powerless individuals process information in a concrete manner as they are dependent on others and feel psychologically proximal with others (Keltner, Gruenfeld, and Anderson 2003; Lee and Tiedens 2001).
Applying the notion of abstract and concrete mindsets to the context of ethicality, previous research has shown that ethical and moral principles are high-level constructs (Eyal and Liberman 2012; Eyal, Liberman, and Trope 2008) and that individuals with abstract mindsets are more likely to adhere to ethical decision making. Furthermore, Rixom and Mishra (2014) show that people with an abstract mindset tend to focus on the greater social good rather than on honesty. The authors explain that under an abstract mindset, the greater social good is seen as a superordinate concern that can justify the decision to violate other ethical principles in order to achieve a goal.
Conversely, individuals with a concrete mindset are less likely to prioritize ethical principles (Eyal and Liberman 2012; Eyal, Liberman, and Trope 2008) and, therefore, less likely to emphasize the greater social good. Rather, as self-interest is a more proximate concern (Kivetz and Tyler 2007), people with a concrete mindset tend to engage in behaviors with outcomes that will benefit the self (Rixom and Mishra 2014).
In sum, we propose that powerful individuals with an abstract mindset are willing to engage in unethical behaviors (i.e., posting a fake review) for a greater social good (i.e., donation to charity), while powerless individuals with a more concrete mindset are willing to do so for a personal gain (i.e., gift card). However, we further postulate that review valence is an important boundary condition for such effects.
The Boundary Effect of Review Valence
We argue that the interaction effect of power and incentive type only applies to situations in which individuals are asked to post positive fake reviews. Specifically, if asked to post negative fake reviews about a competitor, consumers are less likely to engage in unethical behaviors, regardless of their state of power or the incentive type. In other words, people are likely to perceive writing negative fake reviews to be more unethical and immoral than writing positive fake reviews because, when the moral dissonance increases, it is more difficult to justify unethical behaviors (Barkan et al. 2012; Xie et al. 2014).
Based on our conceptual framework shown in Figure 1, we put forth the following hypotheses:

Conceptual model.
Hypothesis 1: Individuals will perceive posting a negative fake review about a competitor as more (a) unethical and (b) immoral than posting a positive fake review about the focal service provider.
Hypothesis 2: When asked to post positive fake reviews, powerful (vs. powerless) individuals will be more likely to post a fake review when the incentive is other-benefiting (vs. self-benefiting).
Hypothesis 3: When asked to post negative fake reviews, the interaction effect of power and incentive type on one’s likelihood of posting a fake review will be attenuated.
Research Design
To test our predictions, we conducted three studies. Study 1 was conducted to develop the stimuli and to verify that the two incentive types did not differ in terms of ethicality and morality ratings (hypothesis 1). The purpose of study 2 is to examine if powerful individuals are more inclined to post fake positive reviews when presented with charity incentives, while individuals who lack power tend to post fake reviews when presented with monetary incentives (hypothesis 2). Finally, study 3 investigated the proposed boundary condition of review valence (hypothesis 3).
Study 1
In study 1, several scenarios were tested using a 2 (review valence: positive vs. negative) × 2 (incentive type: monetary vs. charity) between-subjects design describing a situation in which a restaurant manager asked the participant to write a fake review while offering an incentive in return (see Appendix A for a full list of scenarios). In the positive fake review condition, the restaurant manager asked the participant to give the restaurant a five-star rating and write a positive review, while in the negative fake review condition, the manager asked the participant to give a competitor a one-star rating and to post a negative review. The incentive was either a personal gift card or a donation to a local charity.
After reading the scenario, participants rated the requested action by a four-item, 7-point semantic bipolar scale (ethical/unethical, moral/immoral, self-benefiting/other-benefiting, and selfish/altruistic) that was adapted from Dubois, Rucker, and Galinsky (2015).
Analyses and results
One hundred twenty-two participants (48 female; Mage = 33.25, SD = 11.71) recruited from Amazon’s Mechanical Turk were randomly assigned to one of the four conditions. Table 1 presents the means and standard deviations of study 1 results.
Means and Standard Deviations of Study 1.
Note: SD = standard deviation.
We conducted analyses of variance (ANOVAs) with incentive type as a factor and found that in the positive fake review condition, participants in both the monetary and charity incentive conditions perceived the scenario as equally unethical (F[1, 60] = 0.26, p > .60) and equally immoral (F[1, 60] = 0.62, p > .40). However, participants assigned to the monetary incentive condition perceived the scenario as more self-beneficial (F[1, 60] = 8.18, p < .01) and selfish (F[1, 60] = 3.27, p < .08) than those who were assigned to the charity incentive condition.
Similarly, in the negative fake review condition, participants in both the monetary and charity incentive conditions perceived the scenario as equally unethical (F[1, 58] = 2.39, p > .12) and equally immoral (F[1, 58] = 1.19, p > .27). Again, participants assigned to the monetary incentive condition perceived the scenario as more self-beneficial (F[1, 58] = 25.05, p = .000) and selfish (F[1, 58] = 21.35, p = .000) than those who were assigned to the charity incentive condition, verifying that the scenarios differed in terms of beneficiary but not in terms of morality and ethicality ratings.
To test hypothesis 1, we then assigned codes to the review valence (0 = negative, 1 = positive) and ran another one-way ANOVA. The results indicate that participants assigned to the negative fake review condition perceived the review request as more unethical (Mnegative = 1.82 vs. Mpositive = 2.42; F[1, 120] = 4.03, p < .05) and immoral (Mnegative = 1.82 vs. Mpositive = 2.73; F[1, 120] = 8.97, p < .01) than their counterparts in the positive fake review condition. These results lend support for hypothesis 1.
Study 2
Participants, procedures, and measures
One hundred nineteen participants were recruited (54 female; Mage = 34.13, SD = 11.18) from Amazon’s Mechanical Turk. The design was a 2 (power: high vs. low) × 2 (incentive type: monetary vs. charity) quasi-experiment. Participants read one of the hypothetical scenarios and then answered questions about their likelihood to post a fake review and about their personal demographics.
Study 2 included two independent variables: in order to manipulate incentive type, we presented each participant with one of the two scenarios (incentive type: monetary vs. charity) developed in study 1. The participants’ power was measured by two items adapted from previous research (Dubois, Rucker, and Galinsky 2010; Rucker and Galinsky 2008). Specifically, we asked participants to indicate the extent to which they felt powerful and in control in everyday life on a 7-point Likert-type scale (1 = powerless, lacking control; 7 = powerful, in control; r = .81, p = .000).
The dependent variable was likelihood of posting a fake review. Participants were asked to respond to three items to determine the extent to which they would engage in posting a fake review adapted from Karmarkar and Tormala (2010). Questions were “Please indicate how much you think you would like to write a review”; “Please indicate how interested you would be in writing a review” (1 = not at all, 9 = very much so); and “Please indicate the probability of writing a review” (1 = very low, 9 = very high) (α = .96).
We controlled for self-importance and dependence on others since previous research has shown that power is correlated with these two constructs (Rucker, Dubois, and Galinsky 2011). We assessed self-importance using two items adapted from Rucker, Dubois, and Galinsky (2011): “How important are you as an individual?” (1 = not important at all, 8 = very important) and “I am a person of worth” (1 = totally disagree, 8 = totally agree) (r = .69, p = .000). We measured dependence on others using two items: “When it comes to getting things done, do you depend more on yourself or others?” (1 = completely on myself, 8 = completely on others); and “How much do you value people’s opinions versus your own when making a decision?” (1 = my opinion matters most, 8 = others’ opinions matter most) (r = .51, p = .000). Moreover, we included a mood measure by asking participants how happy or sad they were feeling at the time of the experiment (1 = sad, 7 = happy). By doing so, we could rule out the alternative mechanism of the effect of mood on one’s intention to engage in unethical behaviors (Cialdini, Darby, and Vincent 1973; Dubois, Rucker, and Galinsky 2015).
Results
To assess each participant’s likelihood of posting a fake review, we measured one’s self-reported sense of power and ran a moderation analysis (Hayes 2013; Model 1) with incentive type as the independent variable, power as the moderator, intention to post a fake review as the dependent variable, and self-importance, dependence on others, and mood as covariates. The result shows a significant main effect for incentive type on posting a fake review (b = −5.67, t[112] = −3.70, p < .001), such that participants were more likely to post fake reviews when presented with monetary (vs. charity) incentives. The main effect for power was insignificant (b = −.27, t[112] = −1.14, p > .25). Yet the interaction effect between power and incentive type is significant (b = 1.04, t[112] = 3.40, p < .001) (see Table 2).
Result of Moderation Test for Likelihood of Posting a Fake Review Using PROCESS (Model 1).
To decompose the interaction, we performed a floodlight analysis using the Johnson-Neyman technique. Floodlight analysis illuminates ranges of values of the continuous variable (X) where the simple effect is significant and where it is not (Spiller et al. 2013). Past research shows that performing a median split results in a substantial loss of statistical power from dichotomizing a continuous independent variable, which potentially leads to spurious results (Fitzsimons 2008; Irwin and McClelland 2001; Spiller et al. 2013). Our results indicate that there is a significant negative effect of incentive type on the likelihood of posting a fake review among participants with a sense of power lower than 4.52 (bJN = –.95, SE = .48, p = .05), but not for individuals with power higher than 4.52. In other words, low-power individuals were more likely to post a fake review in the monetary incentive condition than in the charity incentive condition. Approximately 58% of participants fell into this category. This interaction is depicted in Figure 2.

Likelihood of posting a fake review in study 2.
Overall, these results provide partial support for hypothesis 2. Consistent with our predictions, less powerful individuals were more likely to post a fake review when presented with a monetary incentive rather than a charity incentive. Unexpectedly, the incentive type had a minimal impact on powerful individuals’ likelihood to post fake reviews. We argue that this insignificant result can be explained by the fact that high-power individuals tend to have a relatively high propensity to engage in unethical behaviors (Detert, Treviño, and Sweitzer 2008; Piff et al. 2012). Accordingly, the likelihood of writing a fake review was uniformly high among our high-power participants.
Study 3
Participants, procedures, and measures
One hundred eighteen participants were recruited from Amazon’s Mechanical Turk and three individuals were excluded based on the instructional attendance check task (IMC; Oppenheimer, Meyvis, and Davidenko 2009; see Appendix D). The final sample was composed of 115 participants (54 female; Mage = 35.49, SD = 12.50), and they were randomly assigned to one of four conditions in a 2 (power: high vs. low) × 2 (incentive: monetary vs. charity) between-subjects experimental design.
We manipulated power by having participants complete a power recall task (Galinsky, Gruenfeld, and Magee 2003). In the high-power condition, participants were asked to recall and write about a time when they had power over others. In the low-power condition, they were asked to recall and write about a time when they lacked power (see Appendix C). We performed a manipulation check using a single bipolar item measured on a 9-point scale: “The event recall task made me feel powerful (vs.) powerless.” The manipulation for incentive type was identical to study 2, and we used the same dependent variable and control variables as in study 2.
Results
A two-tailed t test on the power manipulation check revealed that high-power participants reported feeling more powerful than low-power participants (Mhigh-power = 5.78 vs. Mlow-power = 4.33; t[113] = −4.33, p = .000). We examined the effect of primed power and incentive type on participants’ intentions to post fake reviews. The results of a two-way ANCOVA showed no main effect of power (F[1, 108] < 1) and incentive type (F[1, 108] < 1). Moreover, the interaction effect of power and incentive type was not significant (F[1, 108] = 1.50, p = .22). The effects of self-importance, dependence on others, and mood were also statistically insignificant (F[1, 108] = 0.04, p = .84; F[1, 108] = 2.71, p = .10; and F[1, 108] = 0.03, p = .87, respectively).
These results support hypothesis 3. Notably, the propensity to post fake reviews among both high- and low-power individuals remained low (i.e., mean scores less than 3.0) across the two incentive conditions. This finding is consistent with study 1 results showing that participants considered writing a negative fake review of a competitor to be more unethical and immoral than writing a positive fake review for the focal service provider.
General Discussion
The main purpose of this research is to identify the effect of incentive type (i.e., self-benefiting vs. other-benefiting) on consumers’ intention to post fake reviews and to determine whether an individual’s sense of power plays a moderating role in that association. The results of study 2 show that powerless individuals are more likely to write fake reviews when presented with monetary (i.e., self-benefiting) incentives than when presented with charity (i.e., other-benefiting) incentives. However, powerful consumers are not influenced by the incentive type and consequently, hypothesis 2 is only partially supported. The results for the powerless are consistent with previous social psychology research stating that individuals with a low sense of power desire to acquire personal benefits (Rixom and Mishra 2014).
The findings of study 3 support hypothesis 3: when asked to post negative fake reviews about a competitor, the joint impact of power and incentive type on an individual’s intention was attenuated. This result is congruent with previous research on WOM and self-enhancement. Previous research has shown that individuals want to be perceived as a “good person,” and therefore, they tend to share things that make them look good (Berger 2014). This evidence suggests that negative fake reviews on third-party platforms are likely to be written by jealous competitors rather than by real customers.
This study makes two theoretical contributions: first, despite the fact that about 25% of reviews posted on Yelp are suspicious (Roberts 2013), the tourism literature is silent on fake reviews. Previous empirical research on the topic is limited to the domain of computer science with a focus on pattern detection (e.g., Ott et al. 2011). However, there is a lack of understanding on what motivates consumers (as opposed to companies) to post fake reviews. We show that monetary (self-benefiting) and charity (other-benefiting) incentives—two prevalent marketing practices—are the main drivers of consumer participation in writing fake reviews.
Second, the study findings reveal that one’s sense of power plays an important role in moderating the relationship between incentive type and consumers’ propensity to post fake reviews. Specifically, powerless individuals are more likely to engage in such unethical behaviors when presented with self-benefiting (vs. other-benefiting) incentives. This finding is incongruent with Dubois, Rucker, and Galinsky’s (2015) results. Focusing on the modality of power (i.e., agentic vs. communal), Dubois, Rucker, and Galinsky (2015) find that high-power individuals tend to engage in unethical behaviors when the behaviors benefit the self, whereas low-power individuals tend to engage in unethical behaviors when the behaviors benefit others. However, their study does not examine situations in which two conflicting ethical principles are involved. In such cases, as in our study, the fundamental modalities are not necessarily applicable. Instead, abstract and concrete mindsets activated by power play a substantial role in an individual’s decision-making processes. Specifically, less powerful people with a concrete mindset focus on helping themselves with a monetary gain, thus justifying their decision to violate an ethical principle.
By examining consumer motivations to post fake reviews, the present study delivers an important message to hospitality and tourism practitioners. It is noteworthy that fake online reviews not only undermine credibility of reviews but also affect consumer choices (Munzel 2016). In turn, these reviews can directly influence business performance (Chevalier and Mayzlin 2006). Hence, it is critical to understand reviewers’ motivation to eradicate fake reviews from online platforms. As such, this research has several practical implications. First, many third-party firms offer reputation management services for hotels and restaurants. Their strategy is to assist their clients by collecting feedback from customers and posting such feedback on online review forums, such as Yelp.com and TripAdvisor.com. A classic way to motivate customers to write reviews is to distribute emails that include monetary incentives, such as gift cards or discount coupons. Although their goal is to obtain genuine evaluations from customers, our findings suggest that this method can unintentionally motivate individuals (especially powerless consumers) to write fake reviews. Furthermore, when a consumer responds to an email request and writes a review, TripAdvisor.com adds the sentence: “Review collected in partnership with this restaurant.” 1 However, such a cue may backfire, because consumers might infer that the review is fake.
Second, as others have suggested (Anderson and Simester 2014; Mayzlin, Dover, and Chevalier 2014), online review forum practitioners might want to follow Expedia.com’s example and allow only verified purchasers to post a review. However, this strategy may lead to inadvertent consequences of reducing the number of reviews (Mayzlin, Dover, and Chevalier 2014).
Finally, even after Amazon’s lawsuit against Fiverr.com, an outsourcing site, there are still some websites with users who advertise “review services” for $5. Our findings suggest that adopting a different incentive method, such as a charity appeal, might prevent users to engage in fake reviews.
Limitations and Future Research
As with any research, the present study is not without limitations. First, it was based on self-reported data, which may or may not accurately describe how individuals act in real-life situations. Thus, future research should develop methods that reflect more realistic situations, for instance, by sending fake review requests to a random sample of participants and recording their responses. Second, past research found that the valence of fake reviews depends on the market situation of a hotel and restaurant. For example, a hotel tends to have more negative fake reviews when located near competitors (Mayzlin, Dover, and Chevalier 2014), and a restaurant whose reputation is less established tends to have more positive fake reviews (Luca and Zervas 2015). However, in our two experiments, such information was missing. Therefore, future research should specify the market situation of a property in a hypothetical scenario. Third, we did not examine linguistic characteristics in fake reviews, which can be an interesting way to detect fake reviews. Thus, future research should investigate the effect of power and incentive type on reviewers’ writing styles in fake reviews.
Footnotes
Appendix A
Appendix B
Appendix C
Appendix D
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors thank the Marriott Foundation for the funding of this research.
