US or Domestic Monetary Policy: Which Matters More for Financial Stability?

When inflation is too low or unemployment too high, central banks cut rates; easier financial conditions improve balance sheets and encourage borrowing, but “this inevitably results in higher debt, which brings with it the risk of financial instability.” This paper asks whether prolonged easing raises financial vulnerability, and whether prolonged easing in the United States does so abroad. The design is deliberately not a shock-identification exercise: the key variable is the “duration” of easing, the number of consecutive quarters in which the eight-quarter moving average of a country’s nominal 2-year sovereign yield declines, and the authors state plainly that “we do not explicitly distinguish between systematic and unexpected monetary policy,” because firm leverage is a slow-moving variable responding more to policy expectations than to small surprises. Vulnerability is measured as market-value leverage – the market value of equity plus the book value of liabilities, over the market value of equity – for 988 publicly listed financial firms in 21 countries (18 advanced economies plus Brazil, Mexico and South Africa) from 1998Q1 to 2014Q4, split by the GICS classification into banks, insurance, real estate, asset management, investment banks and a residual category. In panel regressions with firm fixed effects, lagged macroeconomic controls and Driscoll-Kraay standard errors, one additional quarter of domestic easing raises banking-system leverage by 0.191 at the median, and eight consecutive quarters take a representative banking system from 10.5 to 12.0. The paper’s headline is what happens when US easing duration is added and US firms are dropped: the US coefficient is significant at the 1 percent level for every sector except investment banks, and at two years lifts non-US banking leverage from about 16.7 to 19.6, insurance from 8.2 to 9.0 and investment banks from 5.8 to 6.6 – effects “either equal to those of domestic monetary policy easing (for investment banks and asset managers), greater (for banks), or substantially greater (for insurance, real estate and other financial firms).” Repeating the exercise with the 2-year German Bund yield finds euro area spillovers “both economically and statistically very close to zero,” which the authors attribute to the euro’s far smaller role in global trade and finance – non-US banks issue about $15 trillion of dollar liabilities against only about €4 trillion of euro liabilities issued by non-euro-area banks. Cross-country variation lines up with three characteristics: spillovers are larger where financial development is higher, and smaller where trade openness and gross dollar liabilities are larger, because a weaker dollar mechanically shrinks dollar debt and lowers leverage. That dampening is real but partial – push factors dominate throughout, and firms mostly borrow further against the windfall, so “leverage appears to be pro-cyclical.” What the paper cannot claim is causal identification off exogenous policy surprises; it controls for what might have prompted the easing rather than instrumenting it, and notes that if policymakers ease in response to lower leverage the bias runs toward understating the effect.

Tommaso Mancini-Griffoli | Macro Paper Warehouse

US or Domestic Monetary Policy: Which Matters More for Financial Stability?