This study provides direct evidence of the association between debt–equity conflict and investment efficiency in financially distressed firms. Leveraging a unique institutional setting in Japan, we examine the impact of lender-affiliated directors on the managerial decisions of their borrowers. Although banker-directors do not influence firms at low risks of default, their presence leads to more conservative financial decisions in distressed firms, thereby mitigating shareholder exploitation. They also reduce information frictions to prevent overinvestment and underinvestment. However, despite within-firm efficiency gains, potential spillover effects on other stakeholders raise questions about the broader welfare implications of this debt–equity conflict mitigation.

We build a general equilibrium model with financial frictions that impede monetary policy transmission. Agents with heterogeneous productivity can increase investment by levering up, which increases liquidity risk due to maturity transformation. In equilibrium, more productive agents choose higher leverage than less productive agents, which exposes the more productive agents to greater liquidity risk and makes their investment less responsive to interest rate changes. When monetary policy reduces interest rates, aggregate investment quality deteriorates, which blunts the monetary stimulus and decreases asset liquidation values. This, in turn, reduces loan demand, decreasing the interest rate further and generating a negative spiral. Overall, the allocation of credit is distorted and monetary stimulus can become ineffective even with significant interest rate drops.