The private solution trap in collective action problems across 34 nations - Eugene Malthouse; Charlie Pilgrim; Daniel Sgroi; Michela Accerenzi; Antonio Alfonso; Rana Umair Ashraf; Max Baard; Sanchayan Banerjee; Alexis Belianin; Swagata Bhattacharjee; Mihir Bhattacharya; Pablo Brañas-Garza; et al. (Proceedings of the National Academy of Sciences, 2026)