PHYSICAL ENVIRONMENTAL STIMULI AS TRUST PRECONDITIONS, AFFECTIVE MEDIATION, AND UNPLANNED BUYING BEHAVIOR IN SHOPPING MALLS: EVIDENCE FROM A CROSS-BORDER EMERGING MARKET

Unplanned purchasing in brick-and-mortar retail has received sustained theoretical attention under the Stimulus-Organism-Response (S-O-R) framework, yet the vast majority of empirical work concentrates on digital, e-commerce, and livestreaming environments in high-income economies. Physical shopping malls in emerging markets—where institutional trust is fragile and consumers must first assess basic safety before engaging in hedonic consumption—remain empirically underexplored. This study examines how physical environmental stimuli (hygiene, cleanliness, and security) function as baseline trust preconditions that activate positive affective states, which in turn mediate unplanned buying behavior. A cross-sectional survey of 549 mall visitors in Cúcuta, Colombia—a binational border conurbation with heterogeneous consumer flows—was analyzed through Partial Least Squares Structural Equation Modeling (PLS-SEM) with bias-corrected accelerated bootstrapping (5,000 resamples), heterotrait-monotrait ratio (HTMT) for discriminant validity, full collinearity variance inflation factor (VIF) assessment for common method bias control, and PLSpredict for out-of-sample validation. Physical stimuli exhibited the strongest associations with unplanned purchases (product quality r = 0.237; hygiene/cleanliness r = 0.225; security r = 0.212), exceeding traditional marketing variables (advertising r = 0.082; staff attention r = 0.028) by a factor of three to eight. Affective states operated as a significant complementary mediator (β_indirect = 0.038, 95% BCa CI [0.016, 0.068], VAF = 15.1%), indicating that emotions constitute a real but partial mechanism within the S-O-R chain. These findings reframe the classical flat reading of atmospherics into a hierarchical model with trust preconditions, offering actionable evidence for mall management in institutionally fragile markets.