This paper reviews recent advances in the study of dynamic taxation, considering three main approaches: the dynamic Mirrlees, the parametric Ramsey, and the sufficient statistics approaches. In the first approach, agents' heterogeneous abilities to earn income are private information and evolve...

Chamley (1986) and Judd (1985) showed that, in a standard neoclassical growth model with capital accumulation and infinitely lived agents, either taxing or subsidizing capital cannot be optimal in the steady state. In this paper, we introduce innovation-led growth into the Chamley-Judd...

We examine the problem of optimal taxation in a dynamic economy with imperfectly competitive markets. We find that the optimal tax system will tend to provide subsidies for the purchase of capital goods to offset gaps between price and marginal cost. The average tax on capital income will be...

Might firms' use of data create market power? To explore this hypothesis, we craft a model in which economies of scale in data induce a data-rich firm to invest in producing at a lower marginal cost and larger scale. However, the model uncovers much richer interactions between data, welfare and...

Interest in market power has recently surged among economists in many fields, well beyond its traditional home in industrial organization. This has focused empirical attention on markups, the ratios of price to marginal cost in product markets, and markdowns, the ratios of inputs' marginal...

Shifts in the extent of competition, which affect markup ratios, are possible sources of aggregate business fluctuations. Markups are countercyclical, and booms are times at which the economy operates more efficiently. We begin with a real model in which markup ratios correspond to the prices of...

I derive a formula for the equilibrium distribution of markups in the search- theoretic model of imperfect competition of Butters (1977), Varian (1980), and Burdett and Judd (1983). The level of markups and the sign of the relationship between a seller's markup and its size depends on the extent...

The incorporation of increasing returns and imperfect competition into applied general-equilibrium (AGE) models, beginning with Harris (1984), led to much larger welfare effects from changes such as trade liberalization. But the imperfect competition side of these IO developments has often...

A slanted-L curve is well-suited to represent the non-linearity of the celebrated Phillips curve. We show this using cross-country data of major industrialized economies since 2009, including the inflationary surge of the 2020s. At high unemployment rates, an increase in demand reduces...

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...