Risk and risk aversion are important concepts when modeling how to choose from or rank a set of random variables. This chapter reviews and summarizes the definitions and related findings concerning risk aversion and risk in both a mean-variance and an expected utility decision model context.

We examine the impact of tax policy uncertainty on the irreversible investment decisions of a monopolistically competitive firm. We consider the impact of tax policy in terms of the investment tax credit (ITC) as well as the stochastic tax wedge which determines the after-tax costs of investing....