Moshe Levy wrote an academic paper.
We empirically estimate that approximately 90% of standard option-based
compensation constitutes pay-for-luck. This value is very robust, and
stems from the inherent fact that chance plays a dominant role in
determining firm performance. The impact of a manager on her expected
compensation via the improvement of firm performance is low,
contrast to common wisdom, standard option-based compensation does
not constitute a strong motivating force for rational managers. Indexing
and a high strike price can double an option’s motivational power.