We study identification in a binary choice panel data model with a single \emph{predetermined} binary covariate (i.e., a covariate sequentially exogenous conditional on lagged outcomes and covariates). The choice model is indexed by a scalar parameter $\theta$, whereas the distribution of unit-specific heterogeneity, as well as the feedback process that maps lagged outcomes into future covariate realizations, are left unrestricted. We provide a simple condition under which $\theta$ is never point-identified, no matter the number of time periods available. This condition is satisfied in most models, including the logit one. We also characterize the identified set of $\theta$ and show how to compute it using linear programming techniques. While $\theta$ is not generally point-identified, its identified set is informative in the examples we analyze numerically, suggesting that meaningful learning about $\theta$ is possible even in short panels with feedback.
翻译:我们研究二进制选择面板数据模型中的识别方法,使用单一的\ emph{ predecide} 二进制共变式( 即以滞后结果和共变式为条件的相继相继外源变量 ) 。 选择模式由一个标价参数 $\theta$ 索引化, 而单位特定异质的分布, 以及将时滞结果映射成未来共变实现的反馈程序, 不受限制。 我们提供了一个简单的条件, 即$\ theta$ 从来没有被点定过, 不论可用的时间长短。 这个条件在大多数模型中都得到满足, 包括登录时间段 之一。 我们还用线性编程技术来描述所指定的 $\ theta$ 集, 并展示如何计算它。 虽然 $\theta$ 不是一般的点定值, 但它所指明的集在我们用数字分析的示例中是有用的, 表明即使在短小的小组里, 也有可能用反馈来有意义地学习$\ theta$ 。