In this article I develop a political economic understanding of community‐supported agriculture (CSA). I first develop the relevance of three concepts—economic rents, self‐exploitation, and social embeddedness—to CSA and then introduce a framework that relates CSA farmers’ earnings to the average rate of profit, economic rents, and self‐exploitation. I then examine qualitative and quantitative data from a study of 54 CSAs in California's Central Valley and surrounding foothills to explain the wide range of farmers’ earnings in relation to the characteristics of production of CSAs, the social embeddedness of CSAs, and the farmers’ motivations and rationalities. Qualitative data from interviews are used to interpret the results of an ordinary least squares regression analysis showing that (1) farmers’ age, number of employees, and type of CSA strongly shape farmers' earnings; (2) the moral economy of CSA cuts both ways economically, allowing for the capture of economic rents but more often resulting in self‐exploitation because of farmers’ strong sense of obligation to their members; and (3) farmers’ motivations are diverse, but tend toward low and moderate instrumentalism, meaning that earning an income is often not a high priority relative to other values. The conclusion recommends the need to recognize alternative rationalities but also to discuss and confront strong self‐exploitation in alternative food networks because of the broader political economic context in which they exist.