Twin births are an important instrumental variable for the endogenous fertility decision. However, in many economic settings, twins are not exogenous as dizygotic twinning is known to be correlated with maternal characteristics and fertility treatments. Following the medical literature, we...

Here we present an expository, general analysis of valid post-selection or post-regularization inference about a low-dimensional target parameter in the presence of a very high-dimensional nuisance parameter which is estimated using selection or regularization methods. Our analysis provides a...

In this article the package High-dimensional Metrics (hdm) is introduced. It is a collection of statistical methods for estimation and quantification of uncertainty in high-dimensional approximately sparse models. It focuses on providing confidence intervals and significance testing for...