The nonlinear nexuses between monetary policy, household indebtedness, and household consumption: Evidence from Korea

Household indebtedness in Korea has surged persistently during 2003-2022. Low interest rates, coupled with escalating housing prices, are the key drivers of growing household debt. In this context, monetary tightening may play an opposite role to conventional monetary policy. Moreover, inordinate indebtedness likely acts as a deterrent to household consumption. Using threshold regression, this study explores the nonlinear nexus between monetary policy and household debt, as well as the nexus between household consumption and debt in Korea. The results reveal that an increase in the monetary policy rate boosts household debt in a regime with values beyond the threshold of the nominal (real) housing sales price index approximately 61.3 and 63.9 (80.7) for regressions on the regime-specific nominal and real policy rates, respectively. This implies that monetary tightening can enhance household debt due to high housing price expectations. Furthermore, an increase in household indebtedness suppresses household consumption when the household debt-to-annual GDP ratio is above the thresholds of approximately 84% and 82% for regressions on household debt growth and household debt-to-GDP ratio growth, respectively. These findings suggest that, under low interest rates, in the face of high housing prices and “excessive” household indebtedness, monetary tightening and debt expansion are unviable courses of action for resolving growing household indebtedness and declining household consumption. Therefore, when regulating the policy rate to control household debt and spending effectively, it is crucial to maintain housing prices and household indebtedness at desirable levels. In tandem with this, additional policy instruments such as macroprudential and housing-related fiscal regulations may also be needed to attain financial stability.