How does demand uncertainty affect firms' investment decisions? We examine this question in the context of electricity‐producing firms' planned investments in new power plants. We measure uncertainty about future electricity demand using plausibly exogenous variation in temperature projections across scientific climate models. The results show that uncertainty increases investment in power plants with flexible production technologies, while reducing investment in less flexible technologies. Overall, the net effect of uncertainty on investment is positive when firms have access to flexible investment opportunities. These findings are consistent with models in which production flexibility shapes the investment response to demand uncertainty.

We propose a measure of the valuation gap between debt and equity—debt‐equity spread (DES)—based on the difference between actual and equity‐implied credit spreads. DES predicts cross‐sectional stock and bond returns in opposite directions. This predictability is unique compared to existing mispricing measures and cannot be explained by exposures to various risk factors. High‐DES firms are more likely to issue equity and retire debt, and have more insider equity selling. These findings are consistent with DES capturing relative mispricing between debt and equity, and provide empirical support for the model of partially segmented markets in Greenwood, Hanson, and Liao (2018, Review of Financial Studies 31, 3307–3343).