Comparative-statics results for financial options are often assumed to hold for real options. But the effects of higher volatility need not be increased value and postponed investment. This depends on signs of correlations and what parameters are held constant. For real options, the...

Carbon dioxide emissions may cause global warming. But own emissions have negligible effects for a small nation, which may thus regard carbon taxes as distortionary. Such taxes may have other effects, however. When research and development (R&D) has positive external effects, carbon taxes may...

Lund (2002a) showed in a CAPM-type model how tax depreciation schedules affect required expected returns after taxes. Even without leverage higher tax rates implied lower betas when tax deductions were risk free. Here they are risky, and marginal investment is taxed together with inframarginal...

Even for fully equity-financed firms there may be substantial effects of taxation on the after-tax cost of capital. Among the few studies of these effects, even fewer identify all effects correctly. When marginal investment is taxed together with inframarginal, marginal beta differs from average...