Research Database

This appendix contains seven sections. Section A reports results from running regressions of labor earnings on GDP using data from the PSID, for comparison with the results using HRS data in the body of the paper. Section B examines the relationship between family income, aggregate shocks, and risk preferences in the PSID. Section C gives technical details on the Markov Chain Monte Carlo estimation employed in table 1 of the paper and reports the complete parameter estimates for the regressions summarized in that table. Section D reports results when the relationship between earnings and aggregate shocks is estimated with individual-specific coecients rather than common coecients for each risk-tolerance group. Section E reports results comparable to table 1 of the paper and table D.1 of this appendix using only Social Security covered earnings instead of the combination of Social Security and W-2 earnings. Section F reports robustness checks for tables 2 and 3 of the paper under alternative definitions of the household and the consumption and income variables. Section G reports robustness checks for tables 2 and 3 under an alternative definition of the leisure variable.

Randomness in individual discovery disperses productivities, whereas learning from others keeps productivities together. Long-run growth and persistent earnings inequality emerge when these two mechanisms for knowledge accumulation are combined. This paper considers an economy in which those with more useful knowledge can teach others, with competitive markets assigning students to teachers. In equilibrium, students with an ability to learn quickly are assigned to teachers with the most productive knowledge. This sorting on ability implies large differences in earnings distributions conditional on ability, as shown using explicit formulas for the tail behavior of these distributions.

Using simulations from a multicountry neoclassical growth model, we analyze several post-Brexit scenarios. First, the United Kingdom unilaterally imposes tighter restrictions on FDI and trade from other EU nations. Second, the European Union retaliates and imposes the same restrictions on the UK. Finally, the United Kingdom reduces restrictions on other nations during the post-Brexit transition. Model predictions depend crucially on the policy response of multinationals’ investment in technology capital, accumulated know-how from investments in R&D, brands, and organizations used simultaneously in their domestic and foreign operations.

This essay articulates the principles and practices of New Monetarism, our label for a recent body of work on money, banking, payments, and asset markets. We first discuss methodological issues distinguishing our approach from others: New Monetarism has something in common with Old Monetarism, but there are also important differences; it has little in common with Keynesianism. We describe the principles of these schools and contrast them with our approach. To show how it works, in practice, we build a benchmark New Monetarist model, and use it to study several issues, including the cost of inflation, liquidity and asset trading. We also develop a new model of banking.

We build a variation of the neoclassical growth model in which both wealth shocks (in the sense of wealth destruction) and financial shocks to households generate recessions. The model features three mild departures from the standard model: (1) adjustment costs make it difficult to expand the tradable goods sector by reallocating factors of production from nontradables to tradables; (2) there is a mild form of labor market frictions (Nash bargaining wage setting with Mortensen-Pissarides labor markets); (3) goods markets for nontradables require active search from households wherein increases in consumption expenditures increase measured productivity. These departures provide a novel quantitative theory to explain recessions like those in southern Europe without relying on technology shocks.

We develop a pair of risk measures, health and mortality delta, for the universe of life and health insurance products. A life-cycle model of insurance choice simplifies to replicating the optimal health and mortality delta through a portfolio of insurance products. We estimate the model to explain the observed variation in health and mortality delta implied by the ownership of life insurance, annuities including private pensions, and long-term care insurance in the Health and Retirement Study. For the median household aged 51 to 57, the lifetime welfare cost of market incompleteness and suboptimal choice is 3.2% of total wealth.

We develop a new general equilibrium model of asset pricing and asset trading volume in which agents’ motivations to trade arise due to uninsurable idiosyncratic shocks to agents’ risk tolerance. In response to these shocks, agents trade to rebalance their portfolios between risky and riskless assets. We study a positive question — When does trade volume become a pricing factor? — and a normative question — What is the impact of Tobin taxes on asset trading on welfare? In our model, economies in which marketwide risk tolerance is negatively correlated with trade volume have a higher risk premium for aggregate risk. Likewise, for a given economy, we find that assets whose cash flows are concentrated on states with high trading volume have higher prices and lower risk premia. We then show that Tobin taxes on asset trade have a first-order negative impact on ex-ante welfare, i.e., a small subsidy to trade leads to an improvement in ex-ante welfare. Finally, we develop an alternative version of our model in which asset trade arises from uninsurable idiosyncratic shocks to agents’ hedging needs rather than shocks to their risk tolerance. We show that our positive results regarding the relationship between trade volume and asset prices carry through. In contrast, the normative implications of this specification of our model for Tobin taxes or subsidies depend on the specification of agents’ preferences and non-traded endowments.

What shapes the optimal degree of progressivity of the tax and transfer system? On the one hand, a progressive tax system can counteract inequality in initial conditions and substitute for imperfect private insurance against idiosyncratic earnings risk. On the other hand, progressivity reduces incentives to work and to invest in skills, distortions that are especially costly when the government must finance public goods. We develop a tractable equilibrium model that features all of these trade-offs. The analytical expressions we derive for social welfare deliver a transparent understanding of how preference, technology, and market structure parameters influence the optimal degree of progressivity. A calibration for the U.S. economy indicates that endogenous skill investment, flexible labor supply, and the desire to finance government purchases play quantitatively similar roles in limiting optimal progressivity. In a version of the model where poverty constrains skill investment, optimal progressivity is close to the U.S. value. An empirical analysis on cross-country data offers support to the theory.

We study fiscal and monetary policy in a monetary union with the potential for rollover crises in sovereign debt markets. Member-country fiscal authorities lack commitment to repay their debt and choose fiscal policy independently. A common monetary authority chooses inflation for the union, also without commitment. We first describe the existence of a fiscal externality that arises in the presence of limited commitment and leads countries to over-borrow; this externality rationalizes the imposition of debt ceilings in a monetary union. We then investigate the impact of the composition of debt in a monetary union, that is the fraction of high-debt versus low-debt members, on the occurrence of self-fulfilling debt crises. We demonstrate that a high-debt country may be less vulnerable to crises and have higher welfare when it belongs to a union with an intermediate mix of high- and low-debt members, than one where all other members are low-debt. This contrasts with the conventional wisdom that all countries should prefer a union with low-debt members, as such a union can credibly deliver low inflation. These findings shed new light on the criteria for an optimal currency area in the presence of rollover crises.

We develop a new tractable model of banks' liquidity management and the credit channel of monetary policy. Banks finance loans by issuing demand deposits. Because loans are illiquid, deposit transfers across banks must be settled with reserves. Deposit withdrawals are random, and banks manage liquidity risk by holding a precautionary buffer of reserves. We show how different shocks affect the banking system by altering the trade-off between profiting from lending and incurring greater liquidity risk. Through various tools, monetary policy affects the real economy by altering that trade-off. In a quantitative application, we study the driving forces behind the decline in lending and liquidity hoarding by banks during the 2008 financial crisis. Our analysis underscores the importance of disruptions in interbank markets followed by a persistent decline in credit demand.

What structure of income taxation maximizes the social benefits of redistribution while minimizing the social harm associated with distorting the allocation of labor input? Many authors have advocated scrapping the current tax system, which redistributes primarily via marginal tax rates that rise with income, and replacing it with a flat tax system, in which marginal tax rates are constant and redistribution is achieved via non-means-tested transfers. In this paper we compare alternative tax systems in an environment with distinct roles for public and private insurance. We evaluate alternative policies using a social welfare function designed to capture the taste for redistribution reflected in the current tax system. In our preferred specification, moving to the optimal flat tax policy reduces welfare, whereas moving to the optimal fully nonlinear Mirrlees policy generates only tiny welfare gains. These findings suggest that proposals for dramatic tax reform should be viewed with caution.

Does competition spur productivity? And if so, how does it do so? These have long been regarded as central questions in economics. This essay reviews the literature that makes progress toward answering both questions.

We develop a model of equilibrium price dispersion via retailer search and show that the degree of market segmentation within and across countries cannot be separately identified by good-level price data alone. We augment a set of well-known empirical facts about the failure of the law of one price with data on aggregate intranational and international trade quantities, and calibrate the model to match price and quantity facts simultaneously. The calibrated model matches the data very well and implies that within-country markets are strongly segmented, while international borders contribute virtually no additional market segmentation.

We study the large observed changes in labor supply by married women in the United States over the post–World War II period, a period that saw little change in the labor supply by single women. We investigate the effects of changes in the gender wage gap, the quantitative impact of technological improvements in the production of nonmarket goods, and the potential inferiority of nonmarket goods in explaining the dramatic change in labor supply. We find that small decreases in the gender wage gap can simultaneously explain the significant increases in the average hours worked by married women and the relative constancy in the hours worked by single women and by single and married men. We also find that the impact of technological improvements in the household on married female hours and on the relative wage of females to males is too small for realistic values. Some specifications of the inferiority of home goods match the hours patterns, but they have counterfactual predictions for wages and expenditure patterns.

Does the pattern of social connections between individuals matter for macroeconomic outcomes? If so, where do these differences come from and how large are their effects? Using network analysis tools, we explore how different social network structures affect technology diffusion and thereby a country's rate of growth. The correlation between high-diffusion networks and income is strongly positive. But when we use a model to isolate the effect of a change in social networks, the effect can be positive, negative, or zero. The reason is that networks diffuse ideas and disease. Low-diffusion networks have evolved in countries where disease is prevalent because limited connectivity protects residents from epidemics. But a low-diffusion network in a low-disease environment needlessly compromises the diffusion of good ideas. In general, social networks have evolved to fit their economic and epidemiological environment. Trying to change networks in one country to mimic those in a higher-income country may well be counterproductive.

The Pareto-like tail of the size distribution of firms can arise from random growth of productivity or stochastic accumulation of capital. If the shocks that give rise to firm growth are perfectly correlated within a firm, then the growth rates of small and large firms are equally volatile, contrary to what is found in the data. If firm growth is the result of many independent shocks within a firm, it can take hundreds of years for a few large firms to emerge. This paper describes an economy with both types of shocks that can account for the thick-tailed firm size distribution, high entry and exit rates, and the relatively young age of large firms. The economy is one in which aggregate growth is driven by the creation of new products by both new and incumbent firms. Some new firms have better ideas than others and choose to implement those ideas at a more rapid pace. Eventually, such firms slow down when the quality of their ideas reverts to the mean. As in the data, average growth rates in a cross section of firms will appear to be independent of firm size, for all but the smallest firms.