This essay discusses the reasons for and implications of the decline in real interest rates around the world over the past several decades. It suggests that the decline in interest rates is largely explicable from trends in saving, growth, and markups. In this environment, greater government...

Slack - the underutilization of factors of production - varies systematically with economic development. Using novel and detailed measures of the utilization of labor and capital from a large representative sample of firms in rural and urban Kenya, we show that utilization is increasing in firm...

This paper asks whether increasing productivity in the electricity sector can yield larger long-run GDP gains than suggested by electricity's small share of aggregate economic activity. We answer this question using a dynamic multi-sector model in which electricity is a strong complement to...

What sparked humanity's leap from stagnation to prosperity? What lies at the core of inequality among nations? Unified Growth Theory explores the evolution of societies over the entire course of human history. It uncovers the universal wheels of change that have governed the journey of humanity,...

Cities are often described as engines of economic growth. We assess this statement quantitatively. We focus on two mechanisms: a static agglomeration effect that makes production in bigger cities more efficient, and a dynamic effect whereby urban scale impacts the productivity of invention,...

This paper studies China's four-fold increase in per capita GDP relative to the U.S. between 1995 and 2019. First, we argue that China's growth pattern is very similar to that of several other East Asia economies that initially grew very quickly. Second, we show that a minimalist...

Compared to a half-century ago, inequality in the United states has risen and measured productivity growth has fallen. Concerns about rising inequality have been exacerbated by the observation that prices of goods consumed by the poor have risen faster than prices of goods consumed by the rich....

We quantify the contribution of the largest firms to South Korea's economic performance over the period 1972-2011. Using firm-level historical data, we document a novel fact: firm concentration rose substantially during the growth miracle period. To understand whether rising concentration...

Building on recent advances in the literature on knowledge creation and innovation (notably Carnehl and Schneider (2025), we propose a novel general equilibrium model that explicitly incorporates artificial intelligence (AI) as a decision-enhancing technology capable of interpolating between...

This paper describes the response of the economy to large shocks in a nonlinear production network. While arbitrary combinations of shocks can be studied, it focuses on a sector's tail centrality, which quantifies the effect of a large negative shock to the sector - a measure of the systemic...