From Bang Dang Nguyen and Kaspar Meisner Nielsen:

An efficient managerial labor market should compensate executives according to their contribution to shareholder value. We provide novel empirical evidence about the relationship between executive pay and managerial contribution to value by exploiting the exogenous variation resulting from stock price reactions to sudden deaths. We find, first, that the managerial labor market is characterized by positive sorting: managers with high contributions to value obtain higher pay. We find, second, that executives appear, on average, to retain about 80% of the value they create. Overall, our results are informative about the workings of the managerial labor market.