The granting of stock options to employees who have negligible impact on company performance intuitively violates Holmstrom's (1979) sufficient statistic result. This paper revisits the sufficient statistic question of when to condition a contract on an outside signal in a principal-agent model...

We develop a model of strategic contractual incompleteness that identifies conditions under which principals might omit even costlessly verifiable terms. We then use experiments to test comparative statics predictions of the model. While it is well known that verifiability imperfections can...