We develop a heterogeneous agent, overlapping generations model with nonhomothetic preferences that nests several explanations for the decline in the natural rate of interest (r∗) suggested in the literature: demographic change, a slowdown in productivity growth, a rise in income inequality, and public policy. The model can account for a 2.2 percentage point (pp) decline in r∗ between 1975 and 2015, which is within the range of empirical estimates. Rising income inequality is an important driver (-0.70 pp), and together with demographic change (-0.71 pp) and the slowdown in productivity growth (-1.0 pp) explains most of the decline. Growing public debt is the major counteracting force (+0.31 pp). Permanent income inequality is of greater importance than inequality due to uninsurable income risk, and matching the degree of nonhomotheticity in consumption and savings behavior to empirical estimates is essential for this result. We predict that r∗ will reach a low of 0.38% by 2030, after which a slow reversal will begin. The natural rate will stabilize at 1% in the long run, a low level when compared with the postwar path of r∗ implied by the model. This remains true even if we take into account soaring public debt levels due to the COVID-19 pandemic. Policy can have considerable impact on the level of r∗ through the tax and transfer system.

How does bankruptcy protection affect household balance sheet adjustments and aggregate consumption when credit tightens? Using a tractable model of unsecured consumer credit we quantify the trade-off between the insurance and the creditworthiness effects of bankruptcy in response to tighter credit. We show that bankruptcy dampens the effect of tighter credit on aggregate consumption on impact. This is because it allows borrowers to sustain consumption against severe financial distress. However, by leading to consumers' exclusion from the credit market for a certain period, bankruptcy also reduces their ability to smooth consumption over time, implying a slower recovery. The bankruptcy code establishes how costly it is to default, and, thus, plays a crucial role in determining consumers' bankruptcy decisions and in shaping consumption dynamics. We quantify that the 2005 BAPCPA reform, by making filing for bankruptcy more costly, worsened the negative welfare effects of the subsequent credit tightening.

This paper investigates the long-term effects of conditional cash transfers on school attainment and child labor. To this end, we construct a dynamic heterogeneous agent model, calibrate it with Brazilian data, and introduce a policy similar to the Brazilian. Our results suggest that this type of policy has a very strong impact on educational outcomes, sharply increasing primary school completion. The conditional transfer is also able to reduce the share of working children from 22% to 17%. We then compute the transition to the new steady state and show that the program actually increases child labor over the short run, because the transfer is not enough to completely cover the schooling costs, so children have to work to be able to comply with the program's schooling eligibility requirement. We also evaluate the impacts on poverty, inequality, and welfare.

We propose a novel methodology for solving Heterogeneous Agents New Keynesian (HANK) models with aggregate uncertainty and the Zero Lower Bound (ZLB) on nominal interest rates. Our efficient solution strategy combines the sequence-state Jacobian methodology in Auclert et al. (2021) with a tractable structure for aggregate uncertainty by means of a two-regimes shock structure. We apply the method to a simple HANK model to show that: 1) in the presence of aggregate non-linearities such as the ZLB, a dichotomy emerges between the aggregate impulse responses under aggregate uncertainty against the deterministic case; 2) aggregate uncertainty amplifies downturns at the ZLB, and household heterogeneity increases the strength of this amplification; 3) the effects of forward guidance are stronger when there is aggregate uncertainty.