5.1. Social Media as a Double-Edged Sword for Sustainable Tourism
Our findings reveal a paradox at the heart of the relationship between digital information and sustainable tourist mobility. At the district level, unmanaged cascades reinforce existing spatial hotspots, consistent with the self-reinforcing dynamics predicted by cascade theory [
19,
33]. At the city level, however, aggregate spatial concentration declines significantly over the study window. The two trends together suggest that information cascades neither uniformly concentrate nor uniformly disperse tourists; they operate through two countervailing channels whose outcomes differ by spatial scale. This scale-dependent ambiguity is what makes proactive governance of the digital information environment essential because, in its absence, the hotspot-reinforcing channel is likely to prevail.
The sustainability consequences of this tension extend across all three pillars of sustainable development.
Environmentally, the highest-buzz districts are also the most traffic-congested, with average vehicle speeds falling well below the free-flow levels. Because fuel consumption and CO
2 emissions per vehicle-kilometer rise non-linearly with congestion severity [
51], channeling a disproportionate share of tourist trips into a handful of corridors generates outsized transport emissions relative to those produced by a more dispersed pattern. Beyond motorized transport, concentrated foot traffic in peak districts accelerates wear on public spaces, strains waste collection, and raises ambient noise in mixed-use neighborhoods. Steering tourists into areas where marginal environmental damage per additional visitor is the highest runs counter to the SDG 12 aspiration that information systems should support sustainable consumption.
Socially, reinforcing tourist flows in mixed-use historic districts has direct consequences for residents’ well-being. In Bangkok’s Old City, where major heritage sites sit alongside dense residential communities, heightened congestion reflects the daily friction between visitor activity and the routines of residents who share the same narrow streets and limited transit infrastructure. Nightlife-dominated commercial districts also impose late-night noise, waste, and safety externalities on adjacent residential areas. Where cascades intensify tourist concentration in these contested zones, they amplify overtourism pressures that erode urban livability [
44] and work against the SDG 11 goal of reducing cities’ adverse environmental impacts.
Spatial concentration refers to revenue concentration. When a small set of districts captures a disproportionate share of tourist trips, peripheral communities receive almost no expenditure and are effectively excluded from the festival’s economy. The post-festival shift toward a more dispersed distribution therefore represents a meaningful reallocation of tourism revenue, allowing peripheral districts to develop their own tourism economies rather than serving as bedrooms for a centrally located festival. The strategic governance of the digital information environment can accelerate this redistribution by increasing the visibility of under-visited areas.
Two interpretive caveats deserve explicit treatment in this discussion rather than relegation to the methodological footnotes, because they bear directly on how readers should calibrate the causal claim. The first concerns the distinctive traffic-management context of the Songkran festival. The festival is accompanied by extensive city-managed restrictions, including official road closures around Sanam Luang and the Grand Palace, pedestrian-only zones along Khaosan Road, and rerouting of public transport, all of which depress taxi-derived vehicle speeds independently of any social-media-driven behavioral pull. Three features of our identification strategy disentangle these management-induced effects from the cascade-driven attraction that the model is designed to measure. The panel 2SLS specification with district and date fixed effects (
Table A4, Panel B) absorbs city-wide festival-day shocks that act on all districts simultaneously, including any aggregate component of management-induced traffic congestion. The IV-identified visitation effect of
extra trips per unit of buzz operates on tourist flow rather than on vehicle speed, and within-district within-day buzz movements do not produce a detectable causal effect on the congestion proxy itself (
,
); therefore, the cross-sectional buzz–congestion correlation that originally motivated H4 is best read as the joint footprint of cascade-driven visitation and structural cross-district attractiveness rather than as evidence that buzz mechanically slows traffic. Because management-induced restrictions are concentrated in a small set of historic district corridors and applied uniformly during festival hours, their footprint is captured by the date and district fixed effects rather than by within-district variation in social media buzz. Future work that combines taxi GPS with pedestrian-flow sensors or BTS tap-in/tap-out data would allow a cleaner decomposition of vehicular versus pedestrian congestion sources.
The second caveat concerns whether the IV-identified causal effect is artifactually driven by super-hotspots such as Pathum Wan, whose buzz volume is roughly four times the city average. The Rotemberg-weight diagnostics in
Table A2 directly address this issue. Under the primary All-POI-share instrument, the largest district weight is 0.317 for Bang Na, an outer commercial–residential district that does not appear among the ten highest-buzz destinations, and the effective number of identifying districts is 7.4. The Tweet-share variant, which by construction loads heavily on Pathum Wan (top weight 0.661), still yields an IV coefficient of
, which is statistically indistinguishable from the All-POI-share estimate of
and from the Buzz-POI-share estimate of
. The convergence across instruments built on structurally different identifying districts indicates that the causal buzz effect is shared across quieter and busier districts rather than concentrated on any single high-buzz corridor. This consistency is what allows us to interpret the cascade as a city-wide behavioral mechanism rather than as the empirical signature of one famous shopping district.
However, the robustness of the cascade mechanism also makes strategic interventions viable. The IV-corrected estimate shows that the true behavioral response to social media is substantially stronger than conventional estimates suggest, which implies that DMO content interventions can generate meaningful spatial redistribution. Because this causal effect is strongest in festival windows, such interventions would deliver the largest gains precisely when overtourism pressure is most severe.
5.2. Implications for Information-Based Destination Management
This is an observational study, not an evaluation of a designed intervention such as a digital nudge [
6]; what it identifies is the causal behavioral substrate on which any information-based visitor flow management strategy must rest. The implications below should therefore be read as calibrating guidance for DMOs weighing information-based content strategies rather than as validation of a specific intervention class.
Festival amplification of the cascade effect aligns sustainability needs with intervention leverage in a manner that is both theoretically informative and practically exploitable. Tourist volumes surge during festivals, intensifying congestion, waste generation, and resident disruption [
52], yet our results show that social media responsiveness also peaks under these conditions. Information-based content programs need not operate year-round, then, because concentrated efforts during predictable high-stress windows can deliver disproportionate gains in spatial equity. The concurrent drop in travel-time sensitivity during festivals reinforces this point: tourists become more receptive to digital signals and more willing to venture beyond their immediate vicinity, opening a behavioral window in which redistribution toward peripheral areas meets the least resistance.
The category moderation finding adds a second dimension to the intervention design. Search-good destinations are substantially more buzz-sensitive than experience-good destinations, so content strategies aimed at under-visited shopping or nightlife districts will generate the largest redistribution response, while redirecting spa or restaurant traffic calls for different instruments such as curated recommendation lists or influencer partnerships. The within-category Rating heterogeneity documented in
Section 4.1 further qualifies this guidance: in experience-good categories where high ratings may signal touristic over-commercialization rather than quality, official rating-boosting strategies risk backfiring. This type of differentiation avoids the inefficiency of uniform campaigns and concentrates marketing resources where the sustainability return is highest.
5.3. Theoretical Contributions
This study advances the theoretical literature in four ways. First, it carries information cascade theory [
19] beyond its traditional domains in financial markets and technology adoption into the spatial tourism setting, showing that cascade dynamics, once confined to sequential decision contexts with binary outcomes, also operate in continuous spatial choice settings, where tourists select among geographically distributed alternatives.
Second, it enriches the eWOM literature [
15,
25] by establishing that area-level social media intensity, not merely establishment-level reviews, shapes spatial destination choices. Shifting the unit of analysis from the individual firm to the urban district opens a new line of spatially informed eWOM research that treats the information environment as a geographic field rather than a collection of discrete product evaluations.
Third, the study identifies two empirical boundary conditions for information-based visitor flow management. Situational uncertainty in the form of festival windows amplifies the causal buzz effect. Category heterogeneity drives search goods to respond more strongly than experience goods, with Spa and NightClub/Bar visitors within the experience-good set preferring lower-rated venues. Both boundary conditions have long been proposed conceptually but not empirically established.
Fourth, Bartik shift-share IV estimation [
20,
21] pushes the causal evidence beyond what temporal ordering and placebo tests can deliver. That the IV-corrected effect substantially exceeds the conventional estimate shows that measurement error in sparse social media data systematically attenuates observed effects, a methodological insight with broad implications for the eWOM literature, where social media variables are routinely measured with noise. A triple diagnostic combining Rotemberg-weight decomposition, the Borusyak–Hull test, and panel 2SLS gives future tourism eWOM studies a workable template for credible causal identification.
Beyond these discipline-specific contributions, the study speaks to the broader “twin transition” discourse in sustainable tourism [
7,
8]. The prevailing thesis is that digitalization and environmental sustainability advance in tandem [
53], yet the empirical literature has largely treated them as complementary, while paying limited attention to the tensions between them. Our findings complicate this optimistic reading because the same digital platforms that enable scalable information-based visitor management simultaneously generate organic cascades that reinforce unsustainable spatial concentration. In other words, digitalization is not inherently sustainability-enhancing; its net contribution depends on whether the digital information environment is actively governed or left to amplify market-driven concentration. This conditional view provides a more nuanced theoretical foundation for twin transitions than the standard assumption of mutual reinforcement in the literature.
5.4. Practical Implications for Sustainable Tourism Management
For DMOs and urban planners, our findings suggest a three-stage adaptive management cycle aligned with the twin transition agenda [
7,
8] that includes: The first stage, monitoring, tracks real-time social media buzz by district to flag emerging hotspots before physical overcrowding materializes, enabling pre-emptive rather than reactive management, as follows: The second stage, information-based content governance, proactively generates engaging digital content for under-visited districts with carrying capacity. Because search-good categories are the most buzz-sensitive, campaigns should prioritize these destination types through influencer partnerships and curated local experience features. The third stage, evaluation, closes the loop by using GPS trajectory data to test whether newly governed content actually shifts tourist flows, providing an evidence-based feedback mechanism for the first stage.
Taken as a whole, this monitor–govern–evaluate cycle turns social media from a passive information channel into an active governance instrument for spatial sustainability. It operates through information-environment management rather than through individually targeted choice-architecture manipulation [
11,
12], and whether a specifically designed nudge embedded within this cycle can further improve outcomes is a question for future research. Any such strategy must also attend to the ethical dimension: redirecting tourists toward peripheral areas that lack adequate infrastructure risks displacing overtourism burdens rather than resolving them, and raises questions about the transparency and accountability of content interventions in public information environments [
3].
5.5. Limitations and Future Research
This study had several limitations.
Three caveats deserve to be flagged. In terms of measurement, Twitter is only one platform and is much smaller in Thailand than Facebook or LINE [
54], with a user base that skews urban, young, and bilingual. Visually oriented platforms such as Instagram and TikTok and messaging services such as LINE and WeChat may generate cascades of different intensities and content compositions; therefore, our estimates should be read as a conservative benchmark for the sub-population that Twitter actually reaches. Moreover, the 2019 data capture a pre-pandemic platform landscape in which Twitter occupied a different competitive position; the subsequent rise of algorithmically curated, video-first platforms such as TikTok may generate cascades of different temporal velocities and content modalities, making our text- and timestamp-based estimates a conservative baseline for the visual-platform era. Twitter sparsity and partial geocoding further qualify the buzz variable, but the EWMA smoothing, district and date fixed effects, and the IV-to-OLS coefficient gap [
49] together accommodate this profile.
On the dependent side, the GPS sample is taxi-borne. It over-represents international and upper-middle-class tourists, longer cross-district trips, and evening movement, while under-representing backpackers, public transport commuters, and walking-only tourists. The congestion proxy also captures vehicular rather than pedestrian crowding. Integrating taxi GPS with BTS tap-in/tap-out data, mobile-phone trajectories, or on-site pedestrian surveys would broaden both the sampling frame and the congestion measurement in future work.
On identification, the Bartik instrument is weak in the pre-festival period and we therefore confine IV inference to the During and After windows. The Borusyak–Hull shift-orthogonality test [
21] returns a positive correlation that we attribute to the common-shock structure of Songkran; thus, the causal argument rests on the joint strength of the temporal lag, placebo permutation, three-IV convergence, and diffuse Rotemberg weights rather than on any single diagnostic. Because buzz is measured at the district level rather than the individual level, individual-level causal claims would require an exposure-representativeness assumption that our data do not directly test.
Future work could profitably integrate multiple social media platforms, run experimental designs that manipulate buzz intensity in controlled settings, and follow DMO social media interventions longitudinally to test whether they produce sustained changes in the spatial patterns of tourists. Adding sentiment analysis would also enrich our understanding of how the valence of online discussion differentially shapes spatial choices. Because our buzz variable captures volume rather than valence, we cannot decompose the cascade into attraction-driven and warning-driven components; future work incorporating sentiment classification could test whether negative buzz (e.g., crowding complaints) attenuates or, paradoxically, amplifies the cascade through a curiosity or fear-of-missing-out channel.