We analyze evidence production in merger control as a delegation problem under an inquisitorial and an adversarial competition policy system. Agents' incentives to produce evidence depend critically on the action set of the decision maker. In an inquisitorial system, allowing ex ante for a compromising remedy reduces incentives when compared with the case in which the merger can be either approved or prohibited. In an adversarial system, no such unambiguous results can be derived because the remedial option is never a best-fit for one of the parties. Comparison of both systems reveals that an adversarial system creates larger incentives when the conflict of interest between the involved parties is large. We relate our results to merger control in the US and the EU.