Interpreting individual heterogeneity in terms of probability theory has proved powerful in connecting behaviour at the individual and aggregate levels. Returning to Ricardo's focus on comparative efficiency as a basis for international trade, much recent quantitative equilibrium modeling of the...

Households' and firms' subjective inflation expectations play a central role in macroeconomic and intertemporal microeconomic models. We discuss how subjective inflation expectations are measured, the patterns they display, their determinants, and how they shape households' and firms' economic...

This article adopts a marketing perspective to examine how blockchain technology can facilitate innovation by streamlining the licensing process of intellectual property (IP). It notes that in the traditional world, there can be a tension between inventors and developers when it comes to...

This paper studies the cross-country patterns of risky innovation and growth through the lens of international trade. We use a simple theoretical framework of risky quality upgrading by firms under varying levels of financial development to derive two predictions. First, the mean rate of quality...

Innovation depends on exporting and, in particular, on scale and competition in export markets. We develop a theory featuring (1) quality-segmented markets, (2) step-by-step innovation that moves firms forward along the quality ladder, and (3) escape-the-competition motives for innovation. We...

We analyze how expropriation risk reduces incentives for innovation and reallocates resources from the innovative sector, building on Romer's(1990) model. Our framework predicts the R&D expenditure, the share of human capital in R&D, the number of patents, technical progress, and economic growth...

The nonrivalry of ideas gives rise to increasing returns, a fact celebrated in Paul Romer's recent Nobel Prize. An implication is that the long-run rate of economic growth is the product of the degree of increasing returns and the growth rate of research effort; this is the essence of...

Population growth has declined markedly in almost all major economies since the 1970s. We argue this trend has important consequences for the process of firm dynamics and aggregate growth. We study a rich semi-endogenous growth model of firm dynamics, and show analytically that a decline in...

A long-standing challenge for welfare economics is to develop welfare criteria that can be applied to allocations with different population levels. Such a criterion is essential to resolve the optimal population problem, i.e., the tradeoff between population size and the welfare of each person...

How does the sustainable level of consumption depend on productivity growth and the size and growth rate of the population? What is the effect of uncertainty over these growth rates? I address these questions using a model in which productivity and population growth are stochastic, and social...