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...

Ongoing demographic change will lead to a relative scarcity of raw labor to the effect that output growth will be decreasing in the next decades, a secular stagnation. As physical capital will be relatively abundant, this decrease of output will be accompanied by reductions of asset returns. We...