Monotone Instrumental Variables: With an Application to the Returns to Schooling
提出单调工具变量（MIV）假设及其特例单调处理选择（MTS），研究其单独或与单调处理反应（MTR）结合时的识别能力，并用MTS和MTR假设对教育回报设定上界。
Econometric analyses of treatment response commonly use instrumental variable (IV) assumptions to identify treatment effects. Yet the credibility of IV assumptions is often a matter of considerable disagreement. There is therefore good reason to consider weaker but more credible assumptions. To this end, we introduce monotone instrumental variable (MIV) assumptions and the important special case of monotone treatment selection (MTS). We study the identifying power of MIV assumptions alone and combined with the assumption of monotone treatment response (MTR). We present an empirical application using the MTS and MTR assumptions to place upper bounds on the returns to schooling