Does monetary punishment crowd out pro-social motivation? A natural experiment on hospital length of stay

We study whether the use of monetary incentives might be counter-productive. In particular, we analyse the effect of fining owners of long-term care institutions who prolong length of stay at hospitals. Exploiting a unique natural experiment involving changes in the catchment areas of two large Norwegian hospitals, we find that hospital length of stay are longer in the hospital using fines to reduce length of stay compared with the hospital not using monetary punishment. We interpret these results as examples of monetary incentives crowding-out agents’ intrinsic motivation, leading to a reduction in effort.