By using a different derivation scheme, a new class of two-sided coherent risk measures is constructed in this paper. Different from existing coherent risk measures, both positive and negative deviations from the expected return are considered in the new measure simultaneously but differently. This innovation makes it easy to reasonably describe and control the asymmetry and fat-tail characteristics of the loss distribution and to properly reflect the investor’s risk attitude. With its easy computation of the new risk measure, a realistic portfolio selection model is established by taking into account typical market frictions such as taxes, transaction costs, and value constraints. Empirical results demonstrate that our new portfolio selection model can not only suitably reflect the impact of different trading constraints, but find more robust optimal portfolios, which are better than the optimal portfolio obtained under the conditional value-at-risk measure in terms of diversification and typical performance ratios.

The 2008 financial crisis exemplifies significant uncertainties in corporate financing conditions. We develop a unified dynamic q-theoretic framework where firms have both a precautionary-savings motive and a market-timing motive for external financing and payout decisions, induced by stochastic financing conditions. The model predicts (1) cuts in investment and payouts in bad times and equity issues in good times even without immediate financing needs; (2) a positive correlation between equity issuance and stock repurchase waves. We show quantitatively that real effects of financing shocks may be substantially smoothed out as a result of firms' adjustments in anticipation of future financial crises.

We propose a model of dynamic investment, financing, and risk management for financially constrained firms. The model highlights the central importance of the endogenous marginal value of liquidity (cash and credit line) for corporate decisions. Our three main results are: (1) investment depends on the ratio of marginal q to the marginal value of liquidity, and the relation between investment and marginal q changes with the marginal source of funding; (2) optimal external financing and payout are characterized by an endogenous double‐barrier policy for the firm's cash‐capital ratio; and (3) liquidity management and derivatives hedging are complementary risk management tools.