The Duration of Welfare Spells
估计了福利救济期持续时间的概率分布，发现多数救济期较短，但少数较长，且长期受助者与短期受助者存在可预测差异，建议福利退出策略应针对长期受助者。
Probability distributions for the duration of welfare spells are estimated. The principle guiding the work is that a recipient will not exit from welfare if the expected utility on welfare exceeds the expected utility of welfare. The analysis indicates that while the majority of welfare spells are of short duration, a nontrivial minority of spells are quite long. Those recipients with long spells are found to differ in predictable ways from those experiencing brief spells. This suggests that strategies to move women off welfare are unnecessary in many cases, and should be targeted on those most likely to be long-term recipients. Copyright 1987 by MIT Press.