High implicit discount rates in consumers' energy-efficiency investments have long been a source of controversy. In several recent papers Hassett and Metcalf argue that the uncertainty and irreversibility attendant on such investments, and the resulting option value, account for this anomalously high implicit discounting. Using their model and data, PWP-027 shows that, to the contrary, Hassett's and Metcalf's analysis falls well short of providing an explanation of this pattern.