The Effect of Ambiguity Aversion on Precautionary Effort

This study analyzes the effect of ambiguity aversion on precautionary effort under a two period model when background risk like income risk is added to loss. Precautionary effort only affects the probability of loss occurrence. The sufficient conditions under which a risk averse and ambiguity averse individual makes more effort than a risk averse and ambiguity neutral one are as follows. First, the distribution of background risk changes in type of first order stochastic dominance. Second, the distribution of background risk changes in type of second order stochastic dominance and the utility function shows prudence. In both cases, AAA (absolute ambiguity aversion) should not increase. That is, AAA denotes DAAA (Decreasing Absolute Ambiguity Aversion) or CAAA (Constant Absolute Ambiguity Aversion). The effect of AAA is not observed in the existing literatures which assume a one-period model. In a one period model, the effect of AAA on precautionary effort of a long term may have ignored. Lastly, precautionary effort increases if and only if AAA is not increasing in cases when the background risk follows binary distribution or an individual is risk neutral and ambiguity averse.