Familiar explanations of why hunter-gatherers first took up farming-superior labor productivity, population pressure, or adverse climate-receive little support from recent evidence. Farming would be an unlikely choice without possession-based private property, which appears to have existed among rare groups of sedentary hunter-gatherers who became the first farmers. Our model shows that among them, farming could have benefited first adopters because private possession was more readily established and defended for cultivated crops and domesticated animals than for the diffuse wild resources on which hunter-gatherers relied, thus explaining how farming could have been introduced even without a productivity advantage.