Research Database

This paper presents a full characterization of the equilibrium value set of a Ramsey tax model. More generally, it develops a dynamic programming method for a class of policy games between the government and a continuum of consumers. By selectively incorporating Euler conditions into a strategic dynamic programming framework, we wed two technologies that are usually considered competing alternatives, resulting in a dramatic simplification of the problem.

I prove some theorems for competitive equilibria in the presence of distortionary taxes and other restraints of trade, and use those theorems to motivate an algorithm for (exactly) computing and empirically evaluating competitive equilibria in dynamic economies. Although its economics is relatively sophisticated, the algorithm is so computationally economical that it can be implemented with a few lines in a spreadsheet. Although a competitive equilibrium models interactions between all sectors, all consumer types, and all time periods, I show how my algorithm permits separate empirical evaluation of these pieces of the model and hence is practical even when very little data is available. For similar reasons, these evaluations are not particularly sensitive to how data is partitioned into "trends" and "cycles." I then compute a real business cycle model with distortionary taxes that fits aggregate U.S. time series for the period 1929-50 and conclude that, if it is to explain aggregate behavior during the period, government policy must have heavily taxed labor income during the Great Depression and lightly taxed it during the war. In other words, the challenge for the competitive equilibrium approach is not so much why output might change over time, but why the marginal product of labor and the marginal value of leisure diverged so much and why that wedge persisted so long. In this sense, explaining aggregate behavior during the period has been reduced to a public finance question - were actual government policies distorting behavior in the same direction and magnitude as government policies in the model?

In this paper we make the following three claims. (1), in contradiction with the conventional view according to which the French depression was very different to that observed in the US, we argue that there are more similarities than differences between the French and U.S. experiences and therefore a common explanation should be sought. (2), poor growth in technological opportunities appear neither necessary nor sufficient to account for the French depression. (3), changes in institutional and market regulation appear necessary to account for the overall changes observed over the period. Moreover, we show that the size of these institutional changes may by themselves be enough to quantatively explain the French depression. However, at this time, we have no theory to explain the size or the timing of these changes.

We analyze the Italian economy in the interwar years. In Italy, as in many other countries, the years immmediately after 1929 were characterized by a major slowdown in economic activity as non farm output declined almost 12. We argue that the slowdown cannot be explained solely by productivity shocks and that other factors must have contributed to the depth and duration of the the 1929 crisis. We present a model in which trade restrictions together with wage rigidities produce a slowdown in economic activity that is consistent with the one observed in the data. The model is also consistent with evidence from sectorial disaggregated data. Our model predicts that trade restrictions can account for about 3/4 of the observed slowdown while wage rigidity (monetary shocks) can account for the remaining fourth.

Monetary policy research using time series methods has been criticized for using more information than the Federal Reserve had available in setting policy. To quantify the role of this criticism, we propose a method to estimate a VAR with real-time data while accounting for the latent nature of many economic variables, such as output. Our estimated monetary policy shocks are closely correlated with a typically estimated measure. The impulse response functions are broadly similar across the methods. Our evidence suggests that the use of revised data in VAR analyses of monetary policy shocks may not be a serious limitation.

A necessary feature for equilibrium is that beliefs about the behavior of other agents are rational. We argue that in stationary OLG environments this implies that any future generation in the same situation as the initial generation must do as well as the initial generation did in that situation. We conclude that the existing equilibrium concepts in the literature do not satisfy this condition. We then propose an alternative equilibrium concept, organizational equilibrium, that satisfies this condition. We show that equilibrium exists, it is unique, and it improves over autarky without achieving optimality. Moreover, the equilibrium can be readily found by solving a maximization program.

There are two striking aspects of the recovery from the Great Depression in the United States: the recovery was very weak and real wages in several sectors rose significantly above trend. These data contrast sharply with neoclassical theory, which predicts a strong recovery with low real wages. We evaluate whether New Deal cartelization policies designed to limit competition among firms and increase labor bargaining power can account for the persistence of the Depression. We develop a model of the intraindustry bargaining process between labor and firms that occurred with these policies, and embed that model within a multi-sector dynamic general equilibrium model. We find that New Deal cartelization policies are an important factor in accounting for the post-1933 Depression. We also find that the key depressing element of New Deal policies was not collusion per se, but rather the link between paying high wages and collusion.

This paper analyzes the effects of money injections on interest rates and exchange rates in a model in which agents must pay a Baumol-Tobin style fixed cost to exchange bonds and money. Asset markets are endogenously segmented because this fixed cost leads agents to trade bonds and money only infrequently. When the government injects money through an open market operation, only those agents that are currently trading absorb these injections. Through their impact on these agents’ consumption, these money injections affect real interest rates and real exchange rates. We show that the model generates the observed negative relation between expected inflation and real interest rates. With moderate amounts of segmentation, the model also generates other observed features of the data: persistent liquidity effects in interest rates and volatile and persistent exchange rates. A standard model with no fixed costs can produce none of these features.

In high-tech industries, one important method of diffusion is through employee mobility: many of the entering firms are started by employees from incumbent firms using some of their former employers’ technological know-how. This paper explores the effect of incorporating this mechanism in a general industry framework by allowing employees to imitate their employers’ know-how. The equilibrium is Pareto optimal since the employees “pay” for the possibility of learning their employers’ know-how. The model’s implications are consistent with data from the rigid disk drive industry. These implications concern the effects of know-how on firm formation and survival.

Will an industry with no antitrust policy converge to monopoly, competition or somewhere in between? We analyze this question using a dynamic dominant firm model with rational agents, endogenous mergers and constant returns to scale production. We find that perfect competition and monopoly are always steady states of this model and that there may be other steady states with a dominant firm and a fringe co-existing. Mergers are likely only when supply is inelastic or demand is elastic, suggesting that the ability of a dominant firm to raise price through monopolization is limited. Additionally, as the discount rate increases, it becomes harder to monopolize the industry, because the dominant firm cannot commit to not raising prices in the future.

This paper quantitatively evaluates the hypothesis that deflation can account for much of the Great Depression (1929–33). We examine two popular explanations of the Depression: (1) The “high wage” story, according to which deflation, combined with imperfectly flexible wages, raised real wages and reduced employment and output. (2) The “bank failure” story, according to which deflationary money shocks contributed to bank failures and to a reduction in the efficiency of financial intermediation, which in turn reduced lending and output. We evaluate these stories using general equilibrium business cycle models, and find that wage shocks and banking shocks account for a small fraction of the Great Depression. We also find that some other predictions of the theories are at variance with the data.

We present a class of convex endogenous growth models and analyze their performance in terms of both growth and business cycle criteria. The models we study have close analogs in the real business cycle literature. We interpret the exogenous growth rate of productivity as an endogenous growth rate of human capital. This perspective allows us to compare the strengths of the two classes of models.

To highlight the mechanism that gives endogenous growth models the ability to improve upon their exogenous growth relatives, we study models that are symmetric in terms of human and physical capital formation—our two engines of growth. More precisely, we analyze models in which the technology used to produce human capital is identical to the technologies used to produce consumption and investment goods and in which the technology shocks in the two sectors are perfectly correlated.

In this paper, I provide a possible explanation of why nominally risk-free bonds are essential in monetary economies. I argue that the role of nominal bonds is to serve as record-keeping devices in intertemporal exchanges of money. I show that bonds can only serve this role if they are illiquid (costly to exchange for goods). Finally, I show that in economies in which nominal bonds are essential, welfare and nominal interest rates are both positively associated with the supply of illiquid bonds (if that supply is small).

What determines the relationship between pollution and growth? Are the forces that explain the behavior over time of these quantities potentially useful to understand more generally the relationship between policies and growth? In this paper, we make a first attempt to analyze the equilibrium behavior of two quantities—the level of pollution and the level of income—in a setting in which societies choose, via voting, how much to regulate pollution. Our major finding is that, consistent with the evidence, the relationship between pollution and growth need not be monotone and that the precise equilibrium nature of the relationship between the two variables depends on whether individuals vote over effluent charges or directly restrict the choice of technology. Moreover, our analysis of the pollution problem suggests that, more generally, endogenous policy choices should be taken seriously as potential sources of heterogeneity when studying cross country differences in economic performance.

Market booms are often followed by dramatic falls. To explain this requires an asymmetry in the underlying shocks. A straightforward model of technological progress generates asymmetries that are also the source of growth cycles. Assuming a representative consumer, we show that the stock market generally rises, punctuated by occasional dramatic falls. With high risk aversion, bad news causes dramatic increases in prices. Bad news does not correspond to a contraction of existing production possibilities, but to a slowdown in their rate of expansion. This economy provides a model of endogenous growth cycles in which recoveries and recessions are dictated by the adoption of innovations.

Backus, Kehoe and Kydland (1992), Baxter and Crucini (1995) and Stockman and Tesar (1995) find two major discrepancies between standard international business cycle models with complete markets and the data: In the models, cross-country correlations are much higher for consumption than for output, while in the data the opposite is true; and cross-country correlations of employment and investment are negative, while in the data they are positive. This paper introduces a friction into a standard model that helps resolve these anomalies. The friction is that international loans are imperfectly enforceable; any country can renege on its debts and suffer the consequences for future borrowing. To solve for equilibrium in this economy with endogenous incomplete markets, the methods of Marcet and Marimon (1999) are extended. Incorporating the friction helps resolve the anomalies more than does exogenously restricting the assets that can be traded.

A necessary feature for equilibrium is that beliefs about the behavior of other agents are rational. We argue that in stationary OLG environments this implies that any future generation in the same situation as the initial generation must do as well as the initial generation did in that situation. We conclude that the existing equilibrium concepts in the literature do not satisfy this condition. We then propose an alternative equilibrium concept, organizational equilibrium, that satisfies this condition. We show that equilibrium exists, it is unique, and it improves over autarky without achieving optimality. Moreover, the equilibrium can be readily found by solving a maximization program.

This paper presents a new method for predicting turning points. The paper formally defines a turning point; develops a probit model for estimating the probability of a turning point; and then examines both the in-sample and out-of-sample forecasting performance of the model. The model performs better than some other methods for predicting turning points.

Many manufacturing industries, including the computer industry, have seen large increases in productivity growth rates and have experienced a reduction in average establishment size and a decrease in the variance of the sizes of plants. A vintage capital model is introduced where learning increases productivity on any given technology and firms choose when to adopt a new vintage. In the model, a rise in the rate of technological change leads to a decrease in both the mean and variance of the size distribution.

We introduce two modifications into the standard real business cycle model: habit persistence preferences and limitations on intersectoral factor mobility. The resulting model is consistent with the observed mean equity premium, mean risk free rate and Sharpe ratio on equity. The model does roughly as well as the standard real business cycle model with respect to standard measures. On four other dimensions its business cycle implications represent a substantial improvement. It accounts for (i) persistence in output, (ii) the observation that employment across different sectors moves together over the business cycle, (iii) the evidence of ‘excess sensitivity’ of consumption growth to output growth, and (iv) the ‘inverted leading indicator property of interest rates,’ that high interest rates are negatively correlated with future output.

This paper presents a model of cumulative innovation where firms are heterogeneous in their research ability. We study the optimal reward policy when the quality of the ideas and their subsequent development effort are private information. The optimal assignment of property rights must counterbalance the incentives of current and future innovators. The resulting mechanism resembles a menu of patents that have infinite duration and fixed scope, where the latter increases in the value of the idea. Finally, we provide a way to implement this patent menu by using a simple buyout scheme: The innovator commits at the outset to a price ceiling at which he will sell his rights to a future inventor. By paying a larger fee initially, a higher price ceiling is obtained. Any subsequent innovator must pay this price and purchase its own buyout fee contract.

We show that in a dynamic Heckscher-Ohlin model the timing of a country’s development relative to the rest of the world affects the path of the country’s development. A country that begins the development process later than most of the rest of the world—a late-bloomer—ends up with a permanently lower level of income than the early-blooming countries that developed earlier. This is true even though the late-bloomer has the same preferences, technology, and initial capital stock that the early-bloomers had when they started the process of development. This result stands in stark contrast to that of the standard one-sector growth model in which identical countries converge to a unique steady state, regardless of when they start to develop.

Our objective is to understand how fundamental uncertainty can affect the long-run growth rate and what factors determine the nature of the relationship. Qualitatively, we show that the relationship between volatility in fundamentals and policies and mean growth can be either positive or negative. We identify the curvature of the utility function as a key parameter that determines the sign of the relationship. Quantitatively, we find that when we move from a world of perfect certainty to one with uncertainty that resembles the average uncertainty in a large sample of countries, growth rates increase, but not enough to account for the large differences in mean growth rates observed in the data. However, we find that differences in the curvature of preferences have substantial effects on the estimated variability of stationary objects like the consumption/output ratio and hours worked.

Trade protection remains a prominent feature of the current world economy and likely has significant effects on industries and macroeconomies. In this paper a particular type of policy, price supports, is analyzed in a two-country, dynamic, general equilibrium model. This model brings new perspectives to the analysis in that it is monetary and has labor mobility within countries between the traded-goods and non–traded-goods sectors. It is found that: (1) The introduction of price supports in an economy benefits only the agents currently working in the traded-goods sector. (2) Cooperation among countries in setting policies results in a higher level of price supports than does noncooperation. (3) Price-support policies can importantly affect the transmission of monetary policy effects, introducing permanent changes in real variables where there were none before and even reversing the signs of changes in some variables.

This paper provides a new rationalization for deposit insurance and systemic disintermediations. I consider an environment in which borrowers face no penalty for failing to repay obligations except the loss of their collateral. I assume that this collateral has aggregate risk. For a subset of the exogenous parameters, I demonstrate that an optimal arrangement features deposit insurance. For a strictly smaller set of parameters, it is optimal in some states of the world to have systemic disintermediation and concomitant falls in real output.

In the early 1980’s, the world steel market collapsed. Since the almost exclusive use of iron-ore is in steel production, many iron-ore mines had to be shut down. We divide the major iron-ore producing countries into groups based on the threat of closure faced by iron-ore mines in the respective country. In countries where mines faced no threat of closure, the iron-ore industry had little or no productivity gain over the decade. In countries where mines faced a large threat of closure, the industry typically had productivity gains ranging from 50 to 100 percent, gains that were unprecedented. We then argue that these productivity increases were not driven by new technology or by the closing of low productivity mines. Hence, the productivity gains were driven by continuing mines, using existing technology, increasing their productivity in order to stay in operation.

The behavior of interest rates under the U.S. National Banking System is puzzling because of the apparent presence of persistent and large unexploited arbitrage opportunities for note issuing banks. Previous attempts to explain interest rate behavior have relied on the cost or the inelasticity of note issue. These attempts are not entirely satisfactory. Here we propose a new rationale to solve the puzzle. Inelastic note issuance arises endogenously because the marginal cost of issuing notes is an increasing function of circulation. We build a spatial separation model where some fraction of agents must move each period. Banknotes can be carried between locations; deposits cannot. Taking the model to the data on national banks, we find it matches the movements in long-term interest rates well. It also predicts movements in deposit rates during panics. However, the model displays more inelasticity of notes issuance than is in the data.

This paper proposes a theory of when labor contract should be nominal or, instead, indexed. We find that, contracts should be indexed if prices are difficult to forecast and nominal otherwise. We use a principal-agent model developed by Jovanovic and Ueda (1997), with moral hazard, renegotiation, and where a signal (the nominal value of the sales of the agent) is observed before renegotiation takes place. We show that their result, that the optimal contract is nominal when agents must choose pure strategies, is robust to the case where agents can choose mixed strategies in the sense that, for certain parameters, the optimal contract is still nominal. For other parameters, however, we show that the optimal contract is indexed. Our findings are consistent with two empirical regularities. First prices are more volatile with higher inflation and, second, countries with high inflation tend to have indexed contracts. Our theory suggests that it is because prices are difficult to forecast in high inflation countries that contracts are indexed.

This paper analyzes the effects of money injections on interest rates and exchange rates in a model in which agents must pay a Baumol-Tobin style fixed cost to exchange bonds and money. Asset markets are endogenously segmented because this fixed cost leads agents to trade bonds and money only infrequently. When the government injects money through an open market operation, only those agents that are currently trading absorb these injections. Through their impact on these agents’ consumption, these money injections affect real interest rates and real exchange rates. We show that the model generates the observed negative relation between expected inflation and real interest rates. With moderate amounts of segmentation, the model also generates other observed features of the data: persistent liquidity effects in interest rates and volatile and persistent exchange rates. A standard model with no fixed costs can produce none of these features.

We present a simple theory of the quality of elected officials. Quality has (at least) two dimensions: competence and honesty. Voters prefer competent and honest policymakers, so high-quality citizens have a greater chance of being elected to office. But low-quality citizens have a “comparative advantage” in pursuing elective office, because their market wages are lower than the market wages of high-quality citizens (competence), and/or because they reap higher returns from holding office (honesty). In the political equilibrium, the average quality of the elected body depends on the structure of rewards from holding public office. Under the assumption that the rewards from office are increasing in the average quality of office holders there can be multiple equilibria in quality. Under the assumption that incumbent policymakers set the rewards for future policymakers there can be path dependence in quality.

A sizeable literature has argued that the growth effects of changes in flat rate taxes are small. In this paper, we investigate the relatively unexplored area of the growth effect of changes in the tax structure, in particular, in the progressivity of taxes. Considering such a tax reform seems empirically more relevant than considering changes in flat tax rates. We construct a general equilibrium model of endogenous growth in which there is heterogeneity in income and in the tax rates. We limit heterogeneity to two types, skilled and unskilled, and posit that the probability of staying or becoming skilled in the subsequent period depends positively on expenses on “teacher” time. In the production sector, we consider two sources of growth. In the first, growth arises as a purely external effect on account of production activities of skilled workers. In the second, a portion of the skilled workforce is used to work in research and other productivity enhancing activities and is compensated for it. Our analysis shows that changes in the progressivity of tax rates can have positive growth effects even in situations where changes in flat rate taxes have no effect. Experiments on a calibrated model indicate that the quantitative effects of moving to a flat rate system are economically significant. The assumption made about the engine of growth has an important effect on the impact of a change in progressivity. Quantitatively, welfare is unambiguously higher in a flat rate system when comparisons are made across balanced growth equlibria; however, when the costs of transition to the higher growth equilibrium is taken into account only the currently rich slightly prefer the flat rate system.

Business cycles appear to be large, persistent, and asymmetric relative to the shocks hitting the economy. This observation suggests the existence of an asymmetric amplification and propagation mechanism, which transforms the shocks into the observed movements in aggregate output. This article demonstrates, in a small open economy, how credit constraints can be such a mechanism. The article also shows, however, that the quantitative significance of the amplification which credit constraints can provide is sensitive to the quantitative specification of the underlying economy (especially factor shares).

In this paper we examine the role of social security in an economy populated by overlapping generations of individuals with time-inconsistent preferences who face mortality risk, individual income risk, and borrowing constraints. Agents in this economy are heterogeneous with respect to age, employment status, retirement status, hours worked, and asset holdings. We consider two cases of time-inconsistent preferences. First, we model agents as quasi-hyperbolic discounters. They can be sophisticated and play a symmetric Nash game against their future selves; or they can be naive and believe that their future selves will exponentially discount. Second, we consider retrospective time inconsistency. We find that (1) there are substantial welfare costs to quasi-hyperbolic discounters of their time-inconsistent behavior, (2) social security is a poor substitute for a perfect commitment technology in maintaining old-age consumption, (3) there is little scope for social security in a world of quasi-hyperbolic discounters (with a short-term discount rate up to 15%), and, (4) the ex ante annual discount rate must be at least 10% greater than seems warranted ex post in order for a majority of individuals with retrospective time inconsistency to prefer a social security tax rate of 10% to no social security. Our findings question the effectiveness of unfunded social security in correcting for the undersaving resulting from time-inconsistent preferences.

This study demonstrates that the U.S. equity premium has declined significantly during the last three decades. The study calculates the equity premium using a variation of a formula in the classic Gordon stock valuation model. The calculation includes the bond yield, the stock dividend yield, and the expected dividend growth rate, which in this formulation can change over time. The study calculates the premium for several measures of the aggregate U.S. stock portfolio and several assumptions about bond yields and stock dividends and gets basically the same result. The premium averaged about 7 percentage points during 1926–70 and only about 0.7 of a percentage point after that. This result is shown to be reasonable by demonstrating the roughly equal returns that investments in stocks and consol bonds of the same duration would have earned between 1982 and 1999, years when the equity premium is estimated to have been zero.

This article develops a model which shows that bank deposit contracts can provide allocations superior to those of exchange markets, offering an explanation of how banks subject to runs can attract deposits. Investors face privately observed risks which lead to a demand for liquidity. Traditional demand deposit contracts which provide liquidity have multiple equilibria, one of which is a bank run. Bank runs in the model cause real economic damage, rather than simply reflecting other problems. Contracts which can prevent runs are studied, and the analysis shows that there are circumstances when government provision of deposit insurance can produce superior contracts.

This study tests experimentally whether the ability of subjects to play a noncooperative game’s mixed-strategy equilibrium (to make their play unpredictable) is affected by how much information subjects have about the structure of the game. Subjects played the mixed-strategy equilibrium when they had all the information about other players’ payoffs and actions, but not otherwise. Previous research has shown that players of a game can play a mixed-strategy equilibrium if they observe the actions of all players and use sophisticated Bayesian learning to infer the likely payoffs to other players. The result of this study suggests that the subjects in our experiments did not use sophisticated Bayesian learning. The result also suggests that economists should be careful about assuming in their models that people can easily infer everyone else’s payoffs.

The value of U.S. corporate equity in the first half of 2000 was close to 1.8 times U.S. gross national product (GNP). Some stock market analysts have argued that the market is overvalued at this level. We use a growth model with an explicit corporate sector and find that the market is correctly valued. In theory, the market value of equity plus debt liabilities should equal the value of productive assets plus debt assets. Since the net value of debt is currently low, the market value of equity should be approximately equal to the market value of productive assets. We find that the market value of productive assets, including both tangible and intangible assets and assets used outside the country by U.S. subsidiaries, is currently about 1.8 times GNP, the same as the market value of equity.

The article shows that in a finite-trader version of the Diamond and Dybvig model (1983), the ex ante efficient allocation can be implemented as a unique equilibrium. This is so even in the presence of the sequential service constraint, as emphasized by Wallace (1988), whereby the bank must solve a sequence of maximization problems as depositors contact it at different times. A three-trader example with constant relative risk-aversion utility is used in order to illustrate clearly the requirements that the sequential service constraint imposes on implementation.

The Suffolk Bank in Boston is well known as having been the clearinghouse for virtually all the banknotes that circulated in New England between 1836 and 1858. An examination of 19th century bank balance sheets shows that during and after the U.S. banking Panic of 1837, this private commercial bank also provided some services that today are provided by central banks. These include lending reserves to other banks (providing a discount window) and keeping the payments system operating. Because of Suffolk’s activities, banks in New England fared better than banks elsewhere during the Panic of 1837. And after the panic, when much of the United States suffered a prolonged economic slowdown, New England fared better than the rest of the country, at least partly because of Suffolk’s central bank-like activities.

This article reviews recent work that generalizes a random matching model of money to permit there to be a mix of transactions: some accomplished through the use of tangible media of exchange and the rest through some form of credit. The generalizations are accomplished by specifying assumptions about common knowledge of individual histories that are intermediate between no common knowledge and complete common knowledge. One of the specifications permits a simple representation of the sense in which more common knowledge is beneficial. The other permits a comparison between using outside money and using inside money as a medium of exchange.

Despite wide recognition of their significant role in explaining sustained growth and economic development, uncompensated knowledge spillovers have not yet been fully modeled with a microeconomic foundation. The main purpose of this paper is to illustrate the exchange of knowledge as well as its consequences on agglomerative activity in a general-equilibrium search-theoretic framework. Agents, possessing differentiated types of knowledge, search for partners to exchange ideas and create new knowledge in order to improve production efficacy. When individuals’ types of knowledge are too diverse, a match is less likely to generate significant innovations. We demonstrate the extent of agglomeration has significant implications for the patterns of information flows in economies. Further, by simultaneously determining the patterns of knowledge exchange and the spatial agglomeration of an economy we identify additional channels for interaction between agglomerative activity and knowledge exchange. Finally, contrary to previous work in spatial agglomeration, our model suggests that agglomerative environments may be either under-specialized and under-populated or over-specialized and over-populated relative to the social optimum.