Understanding the determinants of managerial ownership and the link between

Himmelberg et al. (J. Financial Econom. 53 (1999) 353–384) argue that fixed effects estimators should be used in examination of the relationship between managerial ownership and firm performance. I show that managerial ownership, while substantially different across firms, typically changes slowly from year to year within a company. With rational managers maximising long-term utility, small, one-year changes in ownership are not likely to reflect notable changes in incentives that would lead to substantive within-year changes in performance. By relying on within variation, fixed effects estimators may not detect an effect of ownership on performance even if on