Revisiting the Economic Cost of Bank Capital: What Has Changed Since 2017?

Why It Matters

The research quantifies a modest but real cost of higher capital, guiding regulators on the trade‑off between financial stability and corporate borrowing costs, which in turn influences investment and economic growth.

Key Takeaways

• 1% higher risk‑based capital adds 8‑10 bps to corporate spreads.
• Mortgage lending spreads remain statistically unchanged by capital increases.
• Findings hold across data through 2024, including COVID‑19 period.
• Competition indices do not alter the corporate spread pass‑through.
• PRA’s cost‑benefit framework stays robust for capital policy.

Pulse Analysis

Regulators have long wrestled with the tension between bolstering bank resilience and preserving credit flow to the real economy. The original 2017 study by de‑Ramon and Straughan provided a benchmark: each percentage point increase in risk‑based capital translated into a modest uptick in corporate lending spreads. That metric became a cornerstone of the Prudential Regulation Authority’s (PRA) cost‑benefit analysis, informing decisions on capital buffers and risk‑weight calibrations. By revisiting the question with over three decades of data, the new research offers a timely validation of those early conclusions.

The updated analysis expands the econometric framework to include the COVID‑19 pandemic, Basel II/III reforms, and a suite of competition indicators such as the Lerner index and Herfindahl‑Hirschman index. Despite the heightened volatility of the pandemic years, long‑run pass‑through estimates remain tightly clustered around 8‑10 basis points for corporate borrowers, while mortgage spreads show no statistically significant reaction. Short‑run dynamics exhibit greater noise, but the core corporate lending channel persists, underscoring banks’ preference to adjust higher‑risk, higher‑weighted assets when meeting capital targets.

For policymakers, the study delivers a clear signal: the economic cost of stricter capital rules is modest and concentrated in corporate credit markets, which are directly linked to business investment. Maintaining a calibrated capital regime can therefore safeguard financial stability without imposing prohibitive borrowing costs. The robustness of the PRA’s methodology, even after accounting for structural shifts and competition changes, strengthens confidence in future capital policy adjustments and provides a reliable benchmark for international regulators assessing the trade‑offs of prudential reforms.