Recent estimates of the potential growth effects of tax reform vary wildly, ranging from zero to eight percentage points. Using an endogenous growth model, the authors assess which model features and parameter values are important for determining the quantitative impact of tax reform. The quantitative estimates in several recent papers are compared with each other and with some of the evidence from U.S. experience. The authors find that Robert Lucas's conclusion, that tax reform would have little or no impact on the U.S. growth rate, is theoretically robust and consistent with the evidence.

Why do the countries of the world display considerable disparity in long-term growth rates? This paper examines the hypothesis that the answer lies in differences in national public policies that affect the incentives that individuals have to accumulate capital in both its physical and human forms. Our analysis shows that these incentive effects can induce large differences in long-run growth rates. Since many of the key tax rates are difficult to measure, our procedure is an indirect one. We work within a calibrated, two-sector endogenous growth model, which has its origins in the microeconomic literature on human capital formation. We show that national taxation can substantially affect long-run growth rates. In particular, for small open economies with substantial capital mobility, national taxation can readily lead to "development traps" (in which countries stagnate or regress) or to "growth miracles" (in which countries shift from little growth to rapid expansion). This influence of taxation on the rate of economic growth has important welfare implications: in basic endogenous growth models, the welfare cost of a 10 percent increase in the rate of income tax can be 40 times larger than in the basic neoclassical model.

We extend the canonical epidemiology model to study the interaction between economic decisions and epidemics. Our model implies that people cut back on consumption and work to reduce the chances of being infected. These decisions reduce the severity of the epidemic but exacerbate the size of the associated recession. The competitive equilibrium is not socially optimal because infected people do not fully internalize the effect of their economic decisions on the spread of the virus. In our benchmark model, the best simple containment policy increases the severity of the recession but saves roughly half a million lives in the United States.

This paper studies how the impact of monetary policy depends on the distribution of savings from refinancing mortgages. We show that the efficacy of monetary policy is state dependent, varying in a systematic way with the pool of potential savings from refinancing. We construct a quantitative dynamic life-cycle model that accounts for our findings and use it to study how the response of consumption to a change in mortgage rates depends on the distribution of savings from refinancing. These effects are strongly state dependent. We also use the model to study the impact of a long period of low interest rates on the potency of monetary policy. We find that this potency is substantially reduced both during the period and for a substantial amount of time after interest rates renormalize.

We assess the importance of nominal rigidities using a new weekly scanner dataset. We find that nominal rigidities take the form of inertia in reference prices and costs, defined as the most common prices and costs within a given quarter. Reference prices are particularly inertial and have an average duration of roughly one year, even though weekly prices change roughly once every two weeks. We document the relation between prices and costs and find sharp evidence of state dependence in prices. We use a simple model to argue that reference prices and costs are useful statistics for macroeconomic analysis.

We argue that the government-spending multiplier can be much larger than one when the zero lower bound on the nominal interest rate binds. The larger is the fraction of government spending that occurs while the nominal interest rate is zero, the larger is the value of the multiplier. After providing intuition for these results, we investigate the size of the multiplier in a dynamic, stochastic, general equilibrium model. In this model the multiplier e�ect is substantially larger than one when the zero bound binds. Our model is consistent with the behavior of key macro aggregates during the recent financial crisis. We thank the editor, Monika Piazzesi, Rob Shimer, and two anonymous referees for their

In this paper we argue that the primary force behind the large drop in real exchange rates that occurs after large devaluations is the slow adjustment in the prices of nontradable goods and services. Our empirical analysis uses data from five large devaluation episodes: Argentina (2002), Brazil (1999), Korea (1997), Mexico (1994), and Thailand (1997). We conduct a detailed analysis of the Argentinian case using disaggregated consumer price index data, data from our own survey of prices in Buenos Aires, and scanner data from supermarkets. We assess the robustness of our findings by studying large real exchange rate appreciations, medium devaluations, and small exchange rate movements.

In this article, we provide direct evidence on the behaviour of markups in the retail sector across space and time. Markups are measured using gross margins. We consider three levels of aggregation: the retail sector as a whole, the firm, and the product level. We find that: (1) markups are relatively stable over time and mildly procyclical; (2) there is a large regional dispersion in markups; (3) there is a positive cross-sectional correlation between local income and local markups; and (4) differences in markups across regions result from differences in the assortment of goods sold in different regions, not from deviations from uniform pricing. We propose a simple model consistent with these facts.

We study the properties of the carry trade, a currency speculation strategy in which an investor borrows low-interest-rate currencies and lends high-interest-rate currencies. This strategy generates payoffs that are on average large and uncorrelated with traditional risk factors. We argue that these payoffs reflect a peso problem. The underlying peso event features high values of the stochastic discount factor rather than very large negative payoffs.

The carry trade strategy involves selling forward currencies that are at a forward premium and buying forward currencies that are at a forward discount. We compare the payoffs to the carry trade applied to two different portfolios. The first portfolio consists exclusively of developed country currencies. The second portfolio includes the currencies of both developed countries and emerging markets. Our main empirical findings are as follows. First, including emerging market currencies in our portfolio substantially increases the Sharpe ratio associated with the carry trade. Second, bid-ask spreads are two to four times larger in emerging markets than in developed countries. Third and most dramatically, the payoffs to the carry trade for both portfolios are uncorrelated with returns to the U.S. stock market.