The Food Stamp Program and Food Insufficiency
研究发现食品券参与者食物不足率高于合格非参与者，即使控制其他因素后仍如此。作者认为这是逆向选择所致，并用联立方程模型证明控制逆向选择后，参与者与非参与者食物不足概率相同。
Abstract Food stamp participants have higher food insufficiency rates than eligible nonparticipants, even after controlling for other factors. Given the Food Stamp Program's prominent role in the alleviation of hunger, this is a counterintuitive result. We conjecture that these higher rates are due to adverse selection insofar as households more likely to be food insufficient are also more likely to receive food stamps. We establish a theoretical framework to address this adverse selection. Using a simultaneous equation model with two probits, we show that once one controls for this adverse selection, food stamp recipients have the same probability of food insufficiency as nonrecipients.