Repeatedly solving the Aiyagari (1994) model with random parameters, we construct hundreds of examples with multiple stationary equilibria. We never find multiplicity with risk aversion less than ≈ 1.49, depreciation less than ≈ 0.19, or income persistence less than ≈ 0.47, and multiplicity requires a disaster state for income. In cases with multiplicity, the lowest rental rate occurs near depreciation times the capital share. It is possible for the economy, without a change in fundamentals, to transition rationally from a higher-rate equilibrium to one with a lower rental rate, lower inequality, and lower welfare (for most agents). We also construct the first Krusell and Smith (1998) examples with multiple recursive competitive equilibria.
We document that the interest rate response to fiscal stimulus (IRRF) is lower in countries with high inequality or high household debt. To interpret this evidence we develop a model in which households take on debt to maintain a consumption threshold (saving constraint). Now debt-burdened, these households use additional income to deleverage. In economies with more debt-burdened households, increases in government spending tighten credit conditions less (relax credit conditions more), leading to smaller increases (larger declines) in the interest rate. Our theoretical framework predicts that the negative relationship between the IRRF and debt only holds when credit is not restricted. It also predicts that the consumption response to fiscal stimulus is falling in debt and inequality (only during periods of relaxed credit). We perform a series of empirical tests and find support for these predictions. In doing so, we provide context to recent evidence on the debt-dependent effects of government spending by highlighting that the relationship between debt and fiscal effects varies with credit conditions.
We document four features of consumption and income microdata: (1) household-level consumption is as volatile as household income on average, (2) household-level consumption has a positive but small correlation with income, (3) many low-wealth households have marginal propensities to consume near zero, and (4) lagged high expenditure is associated with low contemporaneous spending propensities. Our interpretation is that household expenditure depends on time-varying consumption thresholds where marginal utility discontinuously increases. Our model with consumption thresholds matches the four facts better than does a standard model. Poor households in our model also exhibit “excess sensitivity” to anticipated income declines.
