This article introduces a new data enrichment method that combines revealed data on consumer demand and competitive reactions with stated data on competitive reactions to yet-to-be-enacted, unprecedented marketing policy changes. The authors extend the data enrichment literature to include stated competitive reactions, collected from subject-matter experts through a conjoint experiment. The authors apply their method to investigate hypothetical and unprecedented sales force policy changes of pharmaceutical companies. The results from the data enrichment method have high face validity and lead to various unique insights compared with using revealed data only. The authors find that only a very large sales force decrease initiated by the market leader triggers all competitors to decrease their sales force as well, leading to substantial profit increases for each firm. With respect to sales force allocation, when competitors decrease their sales force, they mainly decrease the reach of detailing across doctors, rather than decreasing the number of details to the most-visited doctors. The proposed data enrichment method provides managers with a powerful tool to, ex ante, predict the consequences of unprecedented marketing policy changes.