The usefulness of socio-demographic variables in predicting purchase decisions: Evidence from machine learning procedures

•Machine learning boosts predictive power of socio-demographics on purchase decision.•Nature of nonlinearity between socio-demographics and purchase decision described.•Propensity score weighting establishes causal effects of socio-demographics.•Seven machine learning procedures including two bio-inspired algorithms compared.•Machine learning used to build theory contributing to computational social science.