This paper develops a machine-learning method that allows researchers to estimate heterogeneous treatment effects with panel data in a setting with many covariates. Our method, which we name the dynamic causal forest (DCF) method, extends the causal-forest method of Wager and Athey (2018) by...

This paper uses a large cross-country survey of business firms to assess their influence on government policies. It is found that influence is associated with larger, government-owned firms that have a high degree of ownership concentration. In contrast, foreign ownership matters little. It is...