Predictive validation of an extended TPB model in Islamic branding: PLSpredict and CVPAT evidence from Muslim and non-Muslim Thai consumers

Purpose Islamic branding research has primarily centred on explanatory models in Muslim-majority contexts, with limited attention to multicultural settings, informational predictors or predictive analytics. This study aims to address these gaps by extending the Theory of Planned Behaviour (TPB) with Islamic Brand Knowledge (IBK) and Islamic Brand Health Benefits (IBH), which reflect religiously grounded practices such as Halal observance and prayer-related consumption norms, and by applying predictive validation techniques to examine brand consumption among Muslim and non-Muslim consumers in Thailand. Design/methodology/approach A cross-sectional survey of 688 Thai consumers was analysed using partial least squares structural equation modelling (PLS-SEM). Predictive performance was evaluated through PLSpredict and the cross-validated predictive ability test (CVPAT), enabling assessment of both explanatory and forecasting power. Findings Subjective Norms, Perceived Behavioural Control, IBK and IBH significantly influenced consumption behaviour, while Compliance and Country of Origin shaped behaviour indirectly through mediators. The extended TPB model accounted for 70.6% of the variance in consumption behaviour and outperformed a linear benchmark in predictive accuracy, confirming its robustness in multicultural contexts. Originality/value This research makes three key contributions. First, it demonstrates the value of integrating informational constructs (IBK, IBH) into TPB, enriching the theoretical understanding of brand-related decision-making. Second, it pioneers the application of predictive validation tools (PLSpredict and CVPAT) in Islamic branding, responding to recent calls for predictive rigour in consumer behaviour research. Third, it highlights the dynamics of Islamic brand consumption across both Muslim and non-Muslim audiences, offering actionable insights for segmentation, communication strategies and multicultural market development.