Instrumental variables and the search for identification: From supply and demand to natural experiments
Instrumental variables and the search for identification: From supply and demand to natural experiments
复制标题
DOI：
10.1257/jep.15.4.69
复制
发表时间：
2001-09-01
影响因子：
8.4
通讯作者：
Krueger, AB
中科院分区：
文献类型：
--
作者：
Angrist, JD;Krueger, AB
工具变量首先在 20 年代用于估计供求弹性，后来用于纠正单方程模型中的测量误差。最近，工具变量已被广泛用于减少因果关系估计中遗漏变量的偏差。直观上，工具变量方法仅使用关键变量的一部分变异性来估计感兴趣的关系；如果工具有效，则该部分与省略的变量无关。我们讨论仪器变量的机制以及构成良好仪器的品质，特别关注源自“自然实验”的仪器。
Instrumental variables was first used in the 1920s to estimate supply and demand elasticities and later to correct for measurement error in single equation models. Recently, instrumental variables have been widely used to reduce bias from omitted variables in estimates of causal relationships. Intuitively, instrumental variables methods use only a portion of the variability in key variables to estimate the relationships of interest; if the instruments are valid, that portion is unrelated to the omitted variables. We discuss the mechanics of instrumental variables and the qualities that make for a good instrument, devoting particular attention to instruments derived from "natural experiments."