Resource management programs use monitoring and sanctioning mechanisms to enforce rules to mitigate social dilemmas like over-extraction from common property resources. Existing literature on enforcement in strategic choice environments provides mixed evidence regarding the relative effectiveness of probability of detection versus severity of sanctions to deter non-compliance. In a controlled laboratory experiment using a linear extraction game, I exogenously vary these deterrence parameters, while keeping expected penalties constant. I test deterrence effectiveness under four distinct compliance regimes that vary harvest quota levels. I find that higher probability of monitoring is more effective at reducing sub-optimal harvest than an equivalent increase in severity of sanctions. Further, a combination of fines and rewards is more effective than fines alone. The results are driven by deterring over-extraction by free riders.