# Every prediction market is also an action market [[Scott Alexander]] makes the point that by putting a price on a predicted outcome, you are always putting a price on *making that outcome happen*. If a prediction market prices an outcome at $(1-X)/share and you buy N shares and then *make the action happen* you’ll make $N*(1-X). The market has implicitly priced taking the action to make that thing happen. Practically, the coupling between prediction and action depends on 1. Buying enough shares to make the action worthwhile for you will not shift the market enough to make it no longer worthwhile and 2. The market is based around something that one person has control over. ### Related * [[Betting markets for research ideas could circumvent expert review killing ideas]]