How to subsidize contributions to public goods: Does the frog jump out of the boiling water?

According to popular belief, frogs are boiled to death when the water is heated gradually. In this paper, we investigate how humans respond to a very slow versus a very steep increase of a subsidy on contributions to a public good. In an experiment, we vary the mode of the increase (gradual versus quick). When the subsidy is raised to an intermediate level, we see a modest effect in either treatment. When the subsidy is raised to a substantial level, there is a strong effect of a quick increase and a modest effect of a gradual increase in the subsidy.