. . . . . "2.63514E-1"^^ . "2.07E2"^^ . "3.87987E-2"^^ . "1.36906E-2"^^ . "https://data.cooperationdatabank.org/vocab/prop/ethnicityUS" . "Felix Oberholzer-Gee" . "Joel Waldfogel" . "Matthew W White" . "2010-02-01:00"^^ . . . "3.90476E-1"^^ . "630"^^ . "630"^^ . "4.5E-1"^^ . . . . . "2"^^ . . "2"^^ . . "2002"^^ . "Published Article" . "Prisoner's Dilemma Game" . "Natural experiment" . "Monetary" . "Stranger" . "One-shot" . . "2020-12-17T00:11:57.257Z"^^ . . . . "2020-12-01T00:00:00.000Z"^^ . .