The last thirty years have witnessed a fundamental change in the regulation of infrastructure industries. Whereas firms were subject to rate of return regulation and protected from entry in the past, they now face various forms of incentive regulation, competition is actively promoted by many regulators, and both regulators and the firms they regulate must often confront rapid technological progress. This paper surveys the literature on the investment implications of different regulatory schemes, highlighting the relevance of modern investment theory, which puts risk and intertemporal issues, such as the irreversibility of much infrastructure investment, center stage. It discusses the impact on regulated monopolists' investment behavior of key regulatory characteristics, namely the price flexibility allowed by the regulator, the length of the regulatory cycle, and the costs the regulator will allow the firm to recover at future regulatory hearings. It also considers the impact of competition, especially the situation where a vertically integrated firm has its operation of a bottleneck asset regulated, on investment by regulated firms and their competitors.

We analyze the optimal hedging policy of a firm that has flexibility in the timing of investment. Conventional wisdom suggests that hedging adds value by alleviating the under-investment problem associated with capital market frictions. However, our model shows that hedging also adds value by allowing investment to be delayed in circumstances where the same frictions would cause it to commence prematurely. Thus, hedging can have the paradoxical effect of reducing investment. We also show that greater timing flexibility increases the optimal quantity of hedging, but has a non-monotonic effect on the additional value created by hedging. These results may help explain the empirical findings that investment rates do not differ between hedgers and non-hedgers, and that hedging propensities do not depend on standard measures of growth opportunities.