One size doesn't fit all: flexible financing as a catalyst for innovation

We develop an inter-temporal model to examine how financing choices influence firm innovation under asymmetric information. The framework incorporates R&D risk and adverse selection, whereby low-quality firms mimic high-quality innovators, generating endogenous screening and financing frictions. Firms choose among bank lending, equity financing, and hybrid financing based on asset composition, cash flow, and innovation risk. Bank lending mitigates moral hazard through collateral and liquidation, making it optimal for low-risk innovation but inefficient for high-risk R&D due to expected liquidation losses. Equity financing supports radical innovation through risk sharing but requires sufficiently high institutional quality to sustain investor participation. Hybrid financing combines these mechanisms and emerges as a response when firms face binding collateral or institutional constraints, expanding the feasibility frontier. Under high institutional quality, financing strategies follow a risk-dependent transition from bank lending to hybrid financing to equity financing. Under low institutional quality, firms that are excluded from external financing must reduce their innovation intensity unless financing constraints are relaxed. We further show that R&D subsidies are generally more effective than risk guarantees, as they relax financing constraints without weakening screening incentives. Our model yields testable predictions linking financing structure to firm characteristics, R&D risk, and institutional quality.