Abstract
The proliferation of multidestination trips provides valuable opportunities for regions to benefit from spillover effects generated by other regions nearby. To better understand the spatial patterns of multidestination travel, we propose a two-stage distance-based model. Results suggest that long-haul tourists (i.e., those who travel far from home) tend to choose a subsequent destination that is closer to the previous destination but farther away from their residences. In addition to sociodemographic and tripographic factors, we recognize the importance of spatial structure effects in determining the travel distance for a multidestination trip. Based on the model estimates, we propose a tourism spillover index to reflect a region’s potential to receive spillover benefits from multidestination tourists leaving a particular region. Finally, we discuss implications for marketing strategies to enhance the attraction potential of specific destinations.
Keywords
Introduction
Spatial spillovers of tourism to nearby destinations are recognized in the literature as a specific type of spatial interaction among tourist destinations (Stöhr 1983; Pyo, Uysal, and Warner 1996; Gooroochurn and Hanley 2005; Li et al. 2011; Marrocu and Paci 2013; Balli, Curry, and Balli 2015). In this type of interaction, there are distinct benefits associated with proximity or spatial groupings of destinations that make them more attractive to tourists who engage in multidestination travel. In the context of tourist flows, spillovers (in this case, arising from spatial externalities) are the indirect or unintentional effects of a tourist destination on tourist flows to other proximate and/or complementary destinations (Yang and Wong 2012b). One way to understand spillover effects is to explore tourists’ multidestination travel patterns from the demand side. As documented by a large body of literature, tourists (especially those who participate in long-haul trips) opt for multidestination itineraries to maximize utility contingent upon cost and time constraints while considering accessibility to alternative multidestination bundles (Hwang and Fesenmaier 2003; Santos, Ramos, and Rey-Maquieira 2012; Yang, Fik, and Zhang 2013; Hyde and Laesser 2009). As an underpinning concept of microeconomics, utility captures the preference among a set of choice alternatives; according to microeconomics theories, one can specify a utility function based on who is making the choice (Ben-Akiva and Lerman 1985). Many scholars have investigated the decision-making processes associated with multidestination travel, either by proposing a theoretical model (Santos, Ramos, and Rey-Maquieira 2011; Tussyadiah, Kono, and Morisugi 2006) or conducting empirical research based on data from tourist surveys (Hwang and Fesenmaier 2003; Tideswell and Faulkner 2003; Wu, Zhang, and Fujiwara 2011; Santos, Ramos, and Rey-Maquieira 2012).
A multidestination tour links several nearby destination regions together, strengthening the spillovers among them. To survive and succeed in an increasingly competitive tourism market, understanding tourist flow spillovers is essential in tourism planning and in the marketing of collaboration opportunities. Effective multidestination tourist planning involves destination marketing organizations (DMOs) and a vast range of tourism stakeholders (Li et al. 2011; Chancellor 2012). As suggested by Beritelli, Bieger, and Laesser (2014), the mobility space of tourists delimits a destination; thus, using variable geometry to identify overlaps between visitor-chosen spaces has become a key activity in the new paradigm of destination management. Within the context of multidestination travel, the variable geometry approach implies that value can be derived from tactical cooperation among adjacent DMOs to offer more comprehensive experiences to specific market segments.
Both macro- and micro-scale studies and models of tourist flows have helped explain tourists’ spatial movements and destination choices (Ryan 2003; Smith 1983). Among macro-models, spatial econometric models have been introduced to capture spillover effects of tourist flows by incorporating a spatial dependence term (Marrocu and Paci 2013; Yang and Fik 2014). A major drawback of various macro- models, however, is that they are typically tailored to fit aggregate data of tourist movements and fail to consider individual heterogeneity (Uysal and Crompton 1985; Eugenio-Martin 2003). Among micro-models, the conventional discrete choice model (DCM) has been widely used to explain the movements and preferences of individual tourists who choose among a set of known alternative destinations (Nicolau and Más 2008; Seddighi and Theocharous 2002). In the context of multidestination travel, endeavors have been devoted to capturing the complicated structure of choice sets in the DCM (Yang, Fik, and Zhang 2013; Wu, Zhang, and Fujiwara 2011). Nevertheless, DCMs are restricted because of computational considerations, and model outcomes only incorporate a handful of destination alternatives (Cameron and Trivedi 2005), while in real life tourists face a large number of destination options (Sirakaya and Woodside 2005). To overcome this limitation, a more flexible distance-based micro-model can be employed to help explain the distance that an individual tourist travels without needing to construct choice sets of destinations (Wynen 2013; Becken and Schiff 2011; Guillet et al. 2011).
To better understand the multidestination travel patterns of tourists and spillover effects of tourist flows associated with multidestination travel, we apply a two-stage distance-based modeling approach in this article. The first-stage equation considers a tourist’s decision to visit a subsequent destination region, whereas the second-stage equation investigates the travel distance between the previous and subsequent destination regions for those opting to engage in multidestination travel. Based on the estimates of this two-stage model, we calibrate a tourism spillover index (TPI) to reflect the potential of subsequent destination regions for tourists originating from a specific previous destination.
We aim to contribute to the current knowledge of tourist flow analysis in several ways. First, the empirical model deciphers the spatial pattern of multidestination travel routes. In particular, two distinct types of spatial structure effects are considered in modeling geographic tourist flows; namely, the competing destination effect and the intervening opportunity effect. The inclusion of these two effects eliminates potential estimation bias, improves the generalizability of the estimation results, and reduces the likelihood of spatially auto-correlated error (Fotheringham 1985; Guldmann 1999). Second, this study extends the discussion on typologies of multidestination travel by depicting the travel pattern with a set of quantitative metrics. Based on some distance-related estimates from the empirical distance–based model, distinct patterns of multidestination travel can be disclosed. Third, the proposed TPI, which can be used to evaluate the potential spillovers triggered by a multidestination tour, is an efficient managerial and marketing tool that can be used by DMOs to (a) better understand the spatial structure of the tourist flow network and (b) select possible destination regions to bundle as tourist products for collaborative marketing (Beritelli, Bieger, and Laesser 2014). The spillover analysis presented in this article introduces a methodology for evaluating destination connections and provides insights on collaborative destination opportunities as viewed through the lens of multidestination travel.
Literature Review
Multidestination Travel
As shown in tourism literature, a large proportion of tourists engage in multidestination travel (i.e., visit more than one destination during a single trip) (Hwang and Fesenmaier 2003; Tideswell and Faulkner 2003; Santos, Ramos, and Rey-Maquieira 2011; Wu, Zhang, and Fujiwara 2011; Hyde and Laesser 2009). Hyde and Laesser (2009) presented a structural theory of vacation and recognized three vacation macrostructures based on the number of destinations visited and itinerary flexibility. Among these three types, stay-put vacations are associated with a single destination, whereas arranged touring and freewheeling touring vacations cover multiple destinations in a single tour. They found that these macrostructures of vacation significantly influence the microelements of tours.
The results of numerous studies have been used to explain multidestination travel preferences from the demand side. By extending Lancaster’s original model of choice sets and consumer bundles, Tussyadiah, Kono, and Morisugi (2006) proposed a theoretic model explaining multidestination travel and suggested that destination bundling creates higher utility for tourists. Santos, Ramos, and Rey-Maquieira (2011) showed that in the context of multidestination travel, tourism demand is intricate and yields both positive and negative income effects, given risk, uncertainty, and imperfect information about destination alternatives. Tideswell and Faulkner (1999) argued that, being cost-efficient and economically rational, multidestination tourism maximizes individuals’ overall utility during a single trip based on the bundled destinations and diversified settings. Moreover, multidestination travel reduces the risk and uncertainty associated with visiting unfamiliar areas (Lue, Crompton, and Stewart 1996); thus, this type of travel is favored by first-time visitors (Hwang, Gretzel, and Fesenmaier 2006). Hyde and Laesser (2009) emphasized the different typologies of multidestination travelers. While tourists who participate in arranged tours make decisions regarding secondary destinations before travel, freewheeling tourists make these decisions during travel.
On the supply side, it has been shown that a destination’s compatibility with previous destinations is an important consideration when tourists make subsequent destination choices for multidestination trips. Bristow, Lieber, and Fesenmaier (1995) and Jeng and Fesenmaier (1998) argued that the increase in utility gained from multidestination tourism is contingent upon the compatibility of each destination included in the itinerary. Jeng and Fesenmaier (1998) used the term “perceived similarity” to describe the compatibility between destinations and asserted that destinations that are geographically proximate to each other are more likely to be perceived as similar by tourists. However, according to Lue, Crompton, and Stewart (1996), cumulative attractiveness is enhanced if the secondary destination is dissimilar from the previous one, because it results in a more diverse tourist experience.
In several studies, researchers have empirically examined the determinants of multidestination tourism. Tideswell and Faulkner (1999) investigated the number of overnight stopovers by international visitors in Queensland, and found similarities in the propensities of various tourists to engage in multidestination trips. Using a negative binomial model on the number of destinations visited, Santos, Ramos, and Rey-Maquieira (2012) highlighted several important factors that influence multidestination travel patterns, including travel distance, trip purposes, trip organization, transportation mode, accommodation type, travel party size, previous visitation experience, and season. Nicolau and Más (2005) suggested that multidestination vacation decision making was a multistage process, where models of multidestination choices were affected by the means of trip organization and the psychographic dimensions, preferences, and perceptions of tourists. Wu, Zhang, and Fujiwara (2011) introduced the concept of future dependence to investigate the multidestination travel of Japanese tourists, where travel patterns are explained by travel time and constraints, assessments of destination diversity, and variety-seeking motivation. Koo, Wu, and Dwyer (2012) found that the dispersal decision (whether to travel outside of major gateways) is contingent upon transportation mode, motivation, the size and nature of the travel group, length of stay, destination familiarity, age, and other demographic considerations. Yang, Fik, and Zhang (2013) recognized the importance of age, past visit history, motivation, and trip organization in tourists’ decisions to either travel to the next destination or return home. Masiero and Zoltan (2013) found that trip characteristics and motivation are important determinants of multidestination travel, whereas demographics are not.
Recognizing the proliferation of multidestination travel, Yang and Wong (2012b) proposed a theoretical framework explaining the plausible channels triggering spillover effects in tourist flows and showed that multidestination trips play an important role in shaping spillovers from the demand side. Other scholars also have acknowledged the multidestination trip as a crucial factor explaining spillovers in tourist flows (Deng and Athanasopoulos 2011; Gooroochurn and Hanley 2005). Although empirical evidence of tourist spillovers has been highlighted in many of these studies, most are couched in macro-modeling frameworks; the micro perspective has been investigated in few, if any. Furthermore, researchers have not examined how multidestination tourist flows are affected by demographic and tripographic information and/or the effects of spatial structure.
Theories and Models of Tourist Flows
Macro-model and spatial interaction theory
The system of tourism flows can be divided into three parts: destinations, origins, and the channels between them. Therefore, one method to explain travel between and within locations from a macro perspective is the spatial interaction model (SIM) (Marrocu and Paci 2013). Since interactions between supply and demand have been identified as the main focus for the study of tourism geography, SIMs are fairly popular in tourism studies (Nepal 2009). Spatial interaction is a common phenomenon that can be regarded as the realized movement of people, commodities, momentary, information, and technology between origins and destinations. Spatial patterns of tourist flows are shaped by spatial interactions between tourist origins and destinations. Since classical Newtonian principles are used to explain these spatial interactions, SIMs are also referred to as gravity models. In a SIM, the spatial interaction between two areas is in proportion to their attractiveness and size, and in inverse proportion to the spatial separation between them.
A gravity-based SIM can be used to identify various origin- and destination-specific factors, as well as separation factors that influence tourist movement. Because of differences in research objectives and study methods, different sets of variables have been selected in previous empirical SIMs. In past literature, major pull factors related to origin attributes include population and income (Marrocu and Paci 2013), whereas important push factors on the destination side consist of income, price, infrastructure, and attraction endowment (Fourie and Santana-Gallego 2011; Khadaroo and Seetanah 2008). The specification of destination attractiveness is vital for SIM applications, and in previous studies, researchers introduced many measures of tourist attraction endowment, such as overall attraction level (Gabe, Lynch, and McConnon 2006), ethnic attraction level (Kliman 1981), shopping opportunity (Tiwari, Doi, and Kawakami 2006), climatic condition (Saayman and Saayman 2008), and coastline length (Eugenio-Martín, Martín-Morales, and Sinclair 2008). Lastly, in SIM applications, beyond geographic distance between origin and destination countries, common spatial separation measures include time distance, linguistic distance (Khadaroo and Seetanah 2008), political distance (Fourie and Santana-Gallego 2011), and cultural distance (Yang and Wong 2012a).
SIMs were originally proposed to capture the pairwise spatial interactions between origins and destinations; therefore, modifications are necessary to incorporate spatial spillovers occurred across destinations. First, in macro-models, spillovers can be partly incorporated by specifying spatial structure effects such as competing destination (CD) effect and intervening opportunity (IO) effect. According to the theory of competition destinations, a clustering of competing destinations can have either positive or negative influences on tourist flows (Fotheringham 1983). On one hand, intense competition between destinations can lower the number of tourist arrivals; on the other hand, an agglomerative force can interconnect these destinations in groups with strengthened attractiveness to tourists (Hanink and Stutts 2002). According to Stouffer’s theory of intervening opportunities, the IO effect is defined for tourist opportunities located between a previous and a subsequent destination where the presence of intervening opportunities is expected to reduce the likelihood of travel between the two destinations (Stouffer 1940). Second, Gooroochurn and Hanley (2005) utilized a simultaneous equation model consisting of two equations to understand the interrelatedness of tourist flows between two destinations. Lastly, Marrocu and Paci (2013) introduced spatial econometric models to capture between-destination interactions by considering tourist flows to neighboring territories via spatial weighting matrices.
Micro-model and random utility theory
Unlike macro-models based on aggregate tourist flow data, micro-models are based on individual-level destination choice data, and many individual-specific demographic and economic variables can be evaluated (Uysal and Crompton 1985). Random utility theory has been frequently adopted to understand tourists’ decision making on destination choice. According to this theory, a rational tourist is expected to compare the utility relative to each choice among a set of alternative destinations and make the decision based on rank-order utility maximization subject to certain constraints (Nicolau and Más 2008). In the context of micro-modeling of tourist movement, the expected utility that a tourist perceives depends on a set of factors such as tourists’ sociodemographic profiles and the attractiveness of destinations as defined by their attributes. Therefore, the preferences of tourists are described by their utility function. To specify this function, Lancaster’s characteristics demand theory highlights the importance to incorporate a set of characteristics or services associated with each destination and the degree to which these characteristics contribute to utility (Lancaster 1971). In tourism literature, Lancaster’s theory has been frequently used to investigate tourist destination choice over space and time (Papatheodorou 2001; Seddighi and Theocharous 2002).
Fusion of macro- and micro-models
In modeling tourist movement, both macro- and micro-models have advantages and disadvantages. To fuse the macro- and micro-modeling approach, Morley, Rosselló, and Santana-Gallego (2014) derived the general SIM formula based on the utility maximization framework from a micro-perspective. Based on a utility function of individual tourists incorporating origin- and destination-specified qualities and a budget constraint covering price information, they obtained an equivalent expression of SIM explaining the aggregate tourist flows from a macro-perspective. Therefore, under certain assumptions, macro- and micro-modeling approaches are theoretically equivalent to each other.
Distance-based models provide alternate ways to fuse macro- and micro-models. It is well known that gravity-based distance decay effects exert a profound attenuating influence on trip patterns as indicated by spatial interaction theory. Plane (1984) derived a formula for estimating inferred distance from a conventional gravity-type model, thus establishing an empirical relationship between the micro- and macro-models of tourist flows. Travel distance is also an important variable in measuring tourism demand (Becken and Schiff 2011), and therefore, distance models can be useful in identifying destination choice factors and for determining the distance traveled by individual tourists during a single trip (Guillet et al. 2011; Wynen 2013; Becken and Schiff 2011).
Zhang et al. (1999) examined the distances traveled by Chinese tourists to national parks and found that travel distance is associated with demographic characteristics, landscape preferences, and attitudes, but not necessarily with tourist motivations, which are numerous and varied. Guillet et al. (2011) employed a distance model to investigate factors affecting the destination choices of outbound Hong Kong tourists. Their results suggest that trip characteristics play a more important role in determining travel distance from the origin to the main destination than other factors such as sociodemographics and travel motivations. Becken and Schiff (2011) confirmed the influence of price in determining the average travel distance per day of New Zealand tourists in two-stage hurdle models. Wynen (2013) utilized the Heckman selection model to analyze determinants of travel distance for same-day visitors in Belgium, and the results highlighted the importance of gender, time spent, age, and information source. To our knowledge, no distance-based model has hitherto been applied to understand the pattern of multidestination travel.
Model and Data
Two-Stage Distance-Based Model
In the empirical analysis, we treat each prefectural city in China as a destination region. We propose a Heckman two-stage model of multidestination tourist flows (Greene 2007; Becken and Schiff 2011), which primarily focuses on the spatial pattern of a multidestination route. The Heckman model alleviates the sample selection bias problem by formulating the two equations as interconnected, and it does not impose any assumptions on the timing of the decision—whether it is made before or during the trip. The first-stage equation captures the decision of whether or not to travel to a subsequent destination (y = 1 if an individual tourist chooses to continue his or her trip) as a conventional probit model, which is specified as
The second-stage distance equation specifies lnD, the log distance between a previous and subsequent destination, as the dependent variable. Note that lnD can be observed if and only if the tourist travels to a subsequent destination. The second-stage equation is specified as
where
Data Description
To estimate the proposed model, we use data from a domestic tourist survey conducted in 13 cities in China’s Jiangsu Province, which was conducted in 2010 under the supervision of the Jiangsu Tourism Administration. Located on the east coast of China, Jiangsu is one of the most developed provinces in the country. It has a total population of approximately 80 million and covers an area of 102,600 km². With affluent tourist resource endowments, Jiangsu attracted total tourist arrivals of about 350 million in 2010, generating total tourism revenue of 468.5 billion CNY, ranking it first among all 31 Chinese provinces. According to statistics from the Jiangsu Tourism Administrative Bureau, tourists’ motivations to visit Jiangsu cover a large spectrum, and its source market covers a broad geographical area that includes almost every prefectural city in China. The structured questionnaire in the tourist survey covered individual sociodemographic information, trip characteristics, and trip satisfaction.
To screen out respondents who were not technically tourists according to the definition of domestic tourists used by the National Tourism Administration of China, only those who had traveled to a destination at least 10 km away from home and had spent at least 6 hours touring were retained in the sample. Before implementing the provincewide survey, the provincial tourism administration assigned a targeted sample size to each city’s tourism bureau according to the estimated number of tourist arrivals in the previous year. Then, the city tourism bureau determined the proportion of the sample to be surveyed at attractions and at tourist accommodations based on historical data on visitor arrivals to major tourist attractions and guest stays at accommodations, respectively. Therefore, the sample from major tourist attractions covers both single-day and overnight tourists, whereas the sample from accommodations covers overnight tourists only. A systematic sampling method was used at major tourist attractions, whereas a stratified sampling method was utilized at tourist accommodations to guarantee the representativeness of subsamples from different types of accommodations such as guest houses, nonrated budget hotels, and star-rated hotels. The detailed sampling method is provided by the Jiangsu Tourism Administration (2001).
As is common in the literature, the modeling effort in this article incorporates a set of independent variables (vector Z) in the first-stage selection equation (Equation 1); more specifically,
age: the age of the tourist (1 = 15–24, 2 = 25–44, 3 = 45–64, 4 = 65 and older);
nights: the number of nights spent at the previous destination;
organization: the organization pattern of the tourist (1 = organized by affiliations, 2 = traveling with friends and relatives, 3 = organized by a travel agency, 4 = traveling alone);
pastvisit: the number of past visits to the previous destination (1 = no past visits, 2 = 1 past visit, 3 = 2–3 past visits, 4 = 4 or more past visits);
distrd1: the geographic distance (in 1,000 km) between the tourist’s residence and the first destination; and
motivation: the major motivation for the trip (1 = leisure/vacation, 2 = sightseeing, 3 = visiting friends and relatives [VFR], 4 = business/conference, 5 = other). Note that this categorization follows the tourist survey questionnaire templates proposed by the National Tourism Administration of China.
The independent variables organization and motivation are also included in the second-stage distance equation (Equation 2). Other independent variables in the second-stage distance equation are as follows:
lndistrd1: log of geographic distance (in 1,000 km) between the tourist’s residence and the first destination;
lndistrd2: log of geographic distance (in 1,000 km) between the tourist’s residence and the subsequent destination;
lnattraction: log of the tourist attraction index of the subsequent destination, defined as the sum of the number of World Heritage Sites (weighted by 4), the number of National Parks (weighted by 2), the number of AAAAA (5A) scenic spots (weighted by 2), and the number of AAAA (4A) scenic spots (weighted by 1) (Zhang 2009). Note that National Parks (literally “National-level Scenic and Historic Interest Areas”) are officially designated by the State Council of China, whereas 5A and 4A scenic spots are evaluated by the National Tourism Administration of China;
lnCD: log of competing destination (CD) index. The CD index measures the accessibility of a destination j to other nearby destinations; and
lnIO: log of intervening opportunity (IO) index.
For a particular previous destination i, the CD effect of a subsequent destination j is assumed to exist among any destinations within a radius of dij (distance between i and j) from j. The CD index is therefore specified as follows:
where i and j index particular previous and subsequent destinations, respectively, and m indexes all competing destinations to destination j (m = 1,…, M). In the equation, dij and djm denote the distances (in 1,000 km) between destinations i and j and between destinations j and m, respectively (Fik 1988; Fik, Amey, and Mulligan 1992). As shown in Figure 2, to define the geographic space of CD effect, we draw a circle centered at j with radius dij (a threshold value to define competing destinations), covering all competing destination points m so that djm ≤ dij.
The IO index is specified as follows:
where n indexes all intervening opportunities between destinations i and j (n = 1, . . ., N). In the equation, din and dnj denote the distances (in 1,000 km) between destinations i and n and between destinations n and j, respectively. As shown in Figure 2, the geographic space of intervening opportunities is defined as the overlapping area of the intersecting circles with radii of dij (a threshold value to define intervening opportunities) from i and j. The IO index sums all tourism opportunities within this space. Following the suggestions from Fik, Amey, and Mulligan (1992), we use a distance-deflated and averaged IO index to alleviate the plausible multicollinearity problem.
In the second-stage distance equation, the estimated coefficients of
To make the explanation of the model estimation results more straightforward, our sample includes only those respondents whose first destination was the city where they were surveyed. Table 1 presents the descriptive statistics of the variables. Our sample is comprised of 30,283 Chinese domestic tourists to Jiangsu. The largest sample (5,587 respondents) was obtained in Nanjing (the capital of Jiangsu), whereas the smallest (973 respondents) was obtained in Suqian (Figure 1). Among all respondents in the sample, 10,492 intended to visit a subsequent destination after visiting Jiangsu (the previous destination). The sampled tourists had an average length of stay of 1.6 days and an average travel distance of 436 km to Jiangsu. The median value of the ordinal variable pastvisit is 2, and the modal value is 1. More specifically, 46.58% of tourists had not visited the destination before, and another 28.49% had visited only once before. For categorical variables, tourists between the ages of 25 and 44 (age = 2) dominated our sample. The distributions of organization and motivation are similar in the first-stage and second-stage equation samples. Around 40% of tourists traveled for sightseeing, while another 24% of tourists visited Jiangsu for vacation. Most tourists traveled with friends and relatives, and a substantial percentage of tourists were organized by affiliations or travel agencies. Table 2 presents the frequencies of 20 most-selected subsequent destinations from our sample, which account for 90.82% of destination choices. The results suggest that most of these destinations are either in Jiangsu or located in other provinces of the Yangtze River Delta area.
Descriptive Statistics for Variables.

Location map of Jiangsu cities.

Geographic space of spatial structure effect.

Geometric typology of multidestination travel based on model estimates.
Frequencies of 20 Most-Selected Subsequent Destinations.
Cities in the Yangtze River Delta area.
Jiangsu cities.
Tourism Spillover Index and GIS Visualization
After obtaining the estimates for the two-stage model, we constructed a tourism spillover index (TSI) to evaluate the magnitude of spillovers arising from multidestination travel. The TSI reflects the total potential of tourists traveling to a particular destination j after visiting a previous destination i, and is defined as follows:
where k indexes the tourist’s origin as a prefectural city in mainland China (k = 1, …, 339; k ≠ j). It is assumed that the overall magnitude of a spillover is the sum of those spillovers contributed by tourists from all possible origins. The index is a sum of the products of two terms. The first term,
where
Considering that tourism is an essentially spatial phenomenon involving the movement of tourists from origins to destinations, geographic information system (GIS) applications have become prominent decision-making tools in tourism planning, trip modeling, and destination management (Chancellor and Cole 2008). As powerful spatial visualization tools, GIS applications have been employed to understand the spatial-temporal patterns of multidestination trips (Wu and Carson 2008). Another powerful GIS application in tourism is geo-demographic marketing analysis: the delineation of geographic market areas based on distance, user and site characteristics, and demographic profiles, as well as the evaluation of market potential for different types of destination products (Feng and Morrison 2002; Miller 2008; Chancellor 2012; Chancellor and Cole 2008). For example, Rutherford, Kobryn, and Newsome (2015) presented a GIS application to assess potential areas for geo-tourism based on tourism access and other factors. To visualize the TSI for each destination region, we applied GIS techniques to present the calibrated TSI values as either spillover generators or receivers. By understanding the patterns revealed in the GIS outputs, DMOs and local tourism authorities are able to better identify potential regions for collaboration and specific market segments to target as multidestination tourists to their regions (Beritelli, Bieger, and Laesser 2014).
Empirical Results
Two-Stage Distance-Based Model
Table 3 presents the estimation results of the two-stage distance-based models. Model 1 is fitted by using all observations. The results from the first-stage selection equation show that out of the three dummy variables for age, only age = 2 is estimated to be statistically significant. Its positive coefficient suggests that compared to younger tourists, those between the ages of 25 and 44 are likely to continue their trips to a subsequent destination. Moreover, nights is estimated to be insignificant. The negative estimate of pastvisit and the positive estimate of distrd1 suggest that first-time and long-haul tourists have a high propensity to travel to a subsequent destination. These findings can be explained by the fact that first-time tourists tend to be more novelty seeking (Tideswell and Faulkner 2003) and long-haul tourists are likely to maximize their utility associated with high travel costs (Yang, Fik, and Zhang 2013). Regarding travel organization patterns and motivations, we find that tourists organized by affiliations (organization = 1) and leisure/vacation and sightseeing tourists (motivation = 1 and 2) are more likely to continue their travel after visiting a destination than other tourists.
Estimation Results of Empirical Models.
Note: Robust standard errors are presented in parentheses. Asterisks indicate significance at the *0.10, **0.05, and ***0.01 levels. AIC = Akaike information criterion; BIC Bayesian information criterion.
For the results from the second-stage distance equation,
To further investigate the role of different travel motivations, we estimated separate models to decipher multidestination travel patterns. The results of Models 2 through 6 are shown in Table 3. In the first-stage selection equation, some results are similar across different the models, such as the estimates of distrd1 and organization. However, the estimated coefficients associated with some independent variables vary greatly across different models. For instance, according to the estimates of age, young tourists less than 24 years of age (age = 1) who travel for leisure/vacation purposes (motivation = 1) are more likely to travel to a subsequent destination (Model 2), whereas their counterparts who travel for sightseeing purposes (motivation = 2) are less likely to do so (Model 3). The number of nights spent at a previous destination also influences the subsequent travel decision for tourists traveling for leisure/vacation (Model 2), sightseeing (Model 3), and VFR (Model 4) purposes. Because of time constraints, a longer stay at a previous destination is associated with a lower probability of travel to another destination (Yang, Fik, and Zhang 2013); hence, a negative coefficient is expected (Koo, Wu, and Dwyer 2010), which is consistent with the results in Models 3 and 4. One possible reason for the positive coefficient of nights in Model 2 is that, for vacationing tourists, a longer duration at the first destination may indicate a large time budget for the entire trip, which enables them to travel to other destinations. The number of past visits is found to determine the likelihood of subsequent travel for tourists traveling for VFR (motivation = 3), business/conference reasons (motivation = 4), and other motivations (motivation = 5) (Models 4–6). For the estimates of the second-stage distance equation,
Models 7–10 in Table 3 provide estimates for subsamples of tourists with different travel organization patterns. The estimates of the first-stage selection equation vary greatly across different models. The age estimates suggest that young tourists less than 24 years of age (age = 1) who are organized by affiliations (organization = 1) are more likely to travel to a subsequent destination than others, whereas their counterparts who travel with friends and relatives (organization = 2) are less likely to continue their trips. Although nights is estimated to be positive in most models, it is found to be negative in Model 8 for tourists traveling with friends and relatives. In the second-stage distance equation, the negative
Tourism Spillover Index
We calibrated the TSI for each prefectural city in China based on a particular Jiangsu city as the spillover generator from Equation 5. We used a Poisson gravity model to predict
where k and i index the origin and destination (more specifically, the previous destination in a multidestination trip), respectively.
Because of space limitations, Figure 4 presents four of the 13 TSI maps, which visualize the spillover potential to all Chinese prefectural cities from four Jiangsu cities: Nanjing, Suzhou, Xuzhou, and Yancheng (highlighted by arrows). Nanjing, the capital of Jiangsu Province, is the largest city and the second largest tourist receiver in the province. Suzhou received the largest number of domestic tourists in 2010. These two cities are located in the southern part of the province. The other two cities, Xuzhou and Yancheng, are located in the northwestern and northeastern parts of the province, respectively. These maps show that TSI generally declines with distance from the spillover generator. As indicated by the large value of TSI, neighboring cities are likely to receive more spillovers. For Nanjing and Xuzhou, most cities with high TSI values are clustered nearby. For Suzhou, two clusters of high TSI values are found: one covers cities nearby, and the other consists of several cities in the northern part of Jiangsu Province and the southern part of Shandong Province. For Yancheng, the city generating few tourism spillovers, only a few neighboring cities are characterized by relatively high TSI values as potential spillover recipients. Lastly, some distant cities from the spillover generators are characterized by high TSI values, such as Beijing, Chongqing, Wuhan, and Luoyang, because of the abundant tourist resources offered there.

Tourism spillover index values of destinations from four Jiangsu cities.
We further obtained the TSI values for different types of tourists according to the estimates from Models 2–10 in Table 3. Figure 5 presents the TSI maps for spillovers generated by tourists with different organization patterns who visited Suzhou (highlighted by the arrow), the most popular domestic tourist destination in Jiangsu. In general, the TSI values decay with distance to Suzhou. Compared to their counterparts in Figure 4, those cities with high TSI values for tourists traveling with friends and relatives (organization = 2) and alone (organization = 4) are relatively scattered over the space, suggesting that many distant cities from Suzhou are also likely to benefit from spillovers generated by the multidestination travel of these two types of tourists. For tourists organized by affiliations (organization = 1), only a few nearby cities are likely to receive substantial spillovers from Suzhou; whereas for tourists organized by travel agencies (organization = 3), the generated spillovers from Suzhou are quite substantial, covering a broad geographic area.

Tourism spillover index values from Suzhou with different organization patterns.
For a specific subsequent destination as a potential spillover receiver, the TSI provides important information on selecting potential collaborators for tourism marketing. We selected Wenzhou, a prefectural city in Zhejiang Province, to illustrate the analysis of TSI for a single spillover receiver. Table 4 presents the TSI values of Wenzhou as a spillover receiver based on 13 different Jiangsu cities as spillover generators. For the spillovers from all tourists, Suzhou contributes most to spillovers, followed by Nanjing and Wuxi. Furthermore, we were able to identify the largest spillover generators based on tourist types. Although Suzhou still produces the largest spillovers from tourists traveling for leisure/vacation (motivation = 1) or VFR (motivation = 3) purposes and those traveling through affiliations (organization = 1), travel agencies (organization = 3) and alone (organization = 4), Nanjing is the largest spillover generator for sightseeing tourists (motivation = 2), Wuxi for business/conference tourists (motivation = 4), and Changzhou for tourists with other motivations (motivation = 5).
Tourism Spillover Index for Wenzhou, Zhejiang Province as a Spillover Receiver.
Note: the bold value indicates the largest value in each column.
Conclusion
In this article, we proposed a two-stage distance-based model to investigate the spatial patterns of multidestination trips. Using the first-stage selection equation, we found that a tourist’s decision to travel to a subsequent destination is determined by the organization pattern, travel motivation, and travel distance from his or her residence to the destination, as well as length of stay and number of past visits to a previous destination. Using the second-stage distance equation, we found the travel distance from the previous to the subsequent destination to be associated with the popularity of tourist attractions, tourists’ organization patterns and motivations, and spatial structure factors (including CD and IO effects). The competing destination effect contributes to an agglomeration force to entice more tourists to travel further to a particular subsequent destination, whereas the intervening opportunities effect impedes multidestination travel when substitutable destinations are located between two destinations. It can be argued that these two distinct spatial structure effects should be accounted for if acceptable parameter estimates for other independent variables are to be found in the second-stage modeling process. The importance of distance-based variables cannot be overlooked based on the geometric typology in Figure 2. Note that it was shown that long-haul tourists travel to subsequent destinations that are closer to the previous one if they opt to continue the tour, whereas generally tourists pick a subsequent destination that is farther away from home than the previous destination.
Our study contributed to the current knowledge of tourist flow analysis in several ways. First, we proposed the two-stage distance-based model to unveil factors determining multidestination travel, and this model was theoretically rooted in one of the most popular theories explaining tourist flows: spatial interaction theory. Second, the geometric typology embedded in the distance-based model provides a concise but wide-ranging insight on the multidestination patterns. Compared to conventional qualitative analysis (Lew and McKercher 2006), our quantitative investigation is able to conduct significance test to discriminate geometric typologies at an aggregate level, and estimated coefficients associated with different typology patterns can be compared and evaluated. Third, we developed a TSI based on the estimation results of the two-stage distance-based model and demonstrated the usefulness of this index in calibrating the market potential for multidestination travelers and targeting potential destination partners for strategical joint-marketing campaigns of different market segments. Last but not least, even though our analysis incorporated only two destinations, the model is flexible in embracing more destinations by assuming the multidestination travel is a Markov-chain process, in which the transition probability of chain states hinges on the probability in the first-step probit equation of our model (Xia, Zeephongsekul, and Packer 2011).
Our research findings provide several important implications for DMOs that could help them internalize spatial spillovers from multidestination tourists. First, as improvements are made to transportation infrastructure and the popularity of self-driving increases, more and more Chinese tourists are likely to make/change destination decisions during their trips. Therefore, DMOs could launch marketing campaigns to attract more tourists by focusing on segments composed of people who are more likely to travel to a subsequent destination. According to the results from our first-stage equation, long-haul tourists are associated with a high probability of multidestination travel; thus, DMOs should increase destination exposure in areas frequented by large numbers of these tourists, such as railway stations and airports. Second, among tourists in different age groups, multidestination travel decisions are driven by different purposes. For example, to encourage multidestination travel among young tourists, vacation products should be the focus, whereas sightseeing products are more likely to entice middle-aged tourists. Third, our results indicate that the popularity of tourist attractions is not a significant factor explaining the travel distance to a subsequent destination for tourists organized by travel agencies. Therefore, for destinations with limited attraction endowments, DMOs are encouraged to work closely with travel agencies to increase the market share of multidestination travelers. Lastly, the competing destination effect was found to be positive and substantial for the VFR segment. Therefore, to leverage this agglomeration effect with neighboring destinations, we recommend that DMOs and attractions offer deep discounts to residents from neighboring cities to nurture this market.
The geometric typology pattern presented in Figure 3 enables DMOs to better understand the spatial movements of tourists and the market potentials of their destinations. Based on the estimates of the two-stage distance model, we proposed a TSI to estimate the potential of a destination to receive spillover benefits from other destinations triggered by multidestination travelers. Therefore, for a particular destination, a myriad of potential collaborators can be found based on the TSI values from other destinations. Implementing a marketing campaign targeting multidestination travelers by promoting an additional trip or side trip requires less effort than marketing a location as a primary or gateway destination, resulting in a higher return on investment. Spillover analysis could help tourism planners and stakeholders understand how tourists move among multiple destinations and recognize destination linkages from a demand perspective, which is useful in identifying potential opportunities for marketing collaboration among different DMOs for the purpose of attracting multidestination travelers. Moreover, those destinations should initiate strategic plans to bundle attractions and activities to augment their overall attractiveness by increasing the gravity effect to entice tourists, ultimately contributing to a competitive advantage for tourism growth (Chancellor 2012). Furthermore, the proposed TSI embraces a flexible framework to integrate additional high-frequency big data sources, such as geo-tagged social media data and cell phone roaming data (Pan and Yang 2016), to monitor and predict the multidestination flow patterns in a real-time fashion.
Several limitations may temper the generalizability of our results. First, the definition of domestic tourist varies across different countries; therefore, our results based on a Chinese sample may not be applicable in other countries. Second, because of data unavailability, we did not investigate the multidestination travel patterns of special-interest tourists such as adventure tourists, eco-tourists, and cultural tourists, which may differ from those of mass tourists. Third, we did not incorporate temporal patterns of multidestination travel; a more comprehensive spatial-temporal analysis of travel patterns deserves further research efforts. In our estimation results, several models have an insignificant ρ value, and further research efforts can be carried out to investigate its theoretic underpinning. Our proposed TSI is able to capture the overall spillover potential for a destination by summing the TSI values over all possible spillover generators. Therefore, in the future, researchers can estimate a two-stage distance-based model using data from a nationwide sample to calculate overall TSI. We also recommend that researchers utilize various permutation methods to calculate confidence intervals for the calibrated TSI values in future work.
Footnotes
Appendix
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 are grateful to the Ministry of Education, the National Tourism Administration, and the National Natural Science Foundation of China (NSFC) for supporting our research through Humanities and Social Sciences Project No. 13YJC790193, Youth Tourism Expert Training Project No. TYETP201525, and NSFC Project No. 41301134. We also gratefully acknowledge the financial support from the China Scholarship Council (201406195033) (award to Dr. Hong-lei Zhang for one year’s visiting scholar research at the Temple University).
