Showing papers by "National Bureau of Economic Research published in 1995"

Comparing Predictive Accuracy

Abstract: We propose and evaluate explicit tests of the null hypothesis of no difference in the accuracy of two competing forecasts. In contrast to previously developed tests, a wide variety of accuracy measures can be used (in particular, the loss function need not be quadratic and need not even be symmetric), and forecast errors can be non-Gaussian, nonzero mean, serially correlated, and contemporaneously correlated. Asymptotic and exact finite-sample tests are proposed, evaluated, and illustrated.

Problems with Instrumental Variables Estimation when the Correlation between the Instruments and the Endogenous Explanatory Variable is Weak

Abstract: We draw attention to two problems associated with the use of instrumental variables (IV), the importance of which for empirical work has not been fully appreciated. First, the use of instruments that explain little of the variation in the endogenous explanatory variables can lead to large inconsistencies in the IV estimates even if only a weak relationship exists between the instruments and the error in the structural equation. Second, in finite samples, IV estimates are biased in the same direction as ordinary least squares (OLS) estimates. The magnitude of the bias of IV estimates approaches that of OLS estimates as the R 2 between the instruments and the endogenous explanatory variable approaches 0. To illustrate these problems, we reexamine the results of a recent paper by Angrist and Krueger, who used large samples from the U.S. Census to estimate wage equations in which quarter of birth is used as an instrument for educational attainment. We find evidence that, despite huge sample sizes, th...

The Limits of Arbitrage

Abstract: In traditional models, arbitrage in a given security is performed by a large number of diversified investors taking small positions against its mispricing. In reality, however, arbitrage is conducted by a relatively small number of highly specialized investors who take large positions using other people's money. Such professional arbitrage has a number of interesting implications for security pricing, including the possibility that arbitrage becomes ineffective in extreme circumstances, when prices diverge far from fundamental values. The model also suggests where anomalies in financial markets are likely to appear, and why arbitrage fails to eliminate them.

Inside the Black Box: The Credit Channel of Monetary Policy Transmission

Abstract: The 'credit channel' theory of monetary policy transmission holds that informational frictions in credit markets worsen during tight- money periods. The resulting increase in the external finance premium--the difference in cost between internal and external funds-- enhances the effects of monetary policy on the real economy. We document the responses of GDP and its components to monetary policy shocks and describe how the credit channel helps explain the facts. We discuss two main components of this mechanism, the balance-sheet channel and the bank lending channel. We argue that forecasting exercises using credit aggregates are not valid tests of this theory.

Natural Resource Abundance and Economic Growth

Abstract: One of the surprising features of modern economic growth is that economies with abundant natural resources have tended to grow less rapidly than natural-resource-scarce economies. In this paper we show that economies with a high ratio of natural resource exports to GDP in 1971 (the base year) tended to have low growth rates during the subsequent period 1971-89. This negative relationship holds true even after controlling for variables found to be important for economic growth, such as initial per capita income, trade policy, government efficiency, investment rates, and other variables. We explore the possible pathways for this negative relationship by studying the cross-country effects of resource endowments on trade policy, bureaucratic efficiency, and other determinants of growth. We also provide a simple theoretical model of endogenous growth that might help to explain the observed negative relationship.

Automatic Lag Selection in Covariance Matrix Estimation

Abstract: We propose a nonparametric method for automatically selecting the number of autocovariances to use in computing a heteroskedasticity and autocorrelation consistent covariance matrix. For a given kernel for weighting the autocovariances, we prove that our procedure is asymptotically equivalent to one that is optimal under a mean squared error loss function. Monte Carlo simulations suggest that our procedure performs tolerably well, although it does result in size distortions.

Myopic loss aversion and the equity premium puzzle

Abstract: The equity premium puzzle refers to the empirical fact that stocks have outperformed bonds over the last century by a surprisingly large margin. We offer a new explanation based on two behavioral concepts. First, investors are assumed to be "loss averse," meaning that they are distinctly more sensitive to losses than to gains. Second, even long-term investors are assumed to evaluate their portfolios frequently. We dub this combination "myopic loss aversion." Using simulations, we find that the size of the equity premium is consistent with the previously estimated parameters of prospect theory if investors evaluate their portfolios annually. There is an enormous discrepancy between the returns on stocks and fixed income securities. Since 1926 the annual real return on stocks has been about 7 percent, while the real return on treasury bills has been less than 1 percent. As demonstrated by Mehra and Prescott [1985], the combination of a high equity premium, a low risk-free rate, and smooth consumption is difficult to explain with plausible levels of investor risk aversion. Mehra and Prescott estimate that investors would have to have coefficients of relative risk aversion in excess of 30 to explain the historical equity premium, whereas previous estimates and theoretical arguments suggest that the actual figure is close to 1.0. We are left with a pair of questions: why is the equity premium so large, or why is anyone willing to hold bonds? The answer we propose in this paper is based on two concepts from the psychology of decision-making. The first concept is loss aversion. Loss aversion refers to the tendency for individuals to be more sensitive to reductions in their levels of well-being than to increases. The concept plays a central role in Kahneman and Tversky's [1979] descriptive theory of decision-making under

Inflation and Economic Growth

Abstract: Data for around 100 countries from 1960 to 1990 are used to assess the effects of inflation on economic performance. If a number of country characteristics are held constant, then regression results indicate that the impact effects from an increase in average inflation by 10 percentage points per year are a reduction of the growth rate of real per capita GDP by 0.2-0.3 percentage points per year and a decrease in the ratio of investment to GDP by 0.4-0.6 percentage points. Since the statistical procedures use plausible instruments for inflation, there is some reason to believe that these relations reflect causal influences from inflation to growth and investment. However, statistically significant results emerge only when high- inflation experiences are included in the sample. Although the adverse influence of inflation on growth looks small, the long-term effects on standards of living are substantial. For example, a shift in monetary policy that raises the long-term average inflation rate by 10 percentage points per year is estimated to lower the level of real GDP after 30 years by 4-7%, more than enough to justify a strong interest in price stability.

Crime and Social Interactions

Abstract: The high degree of variance of crime rates across space (and across time) is one of the oldest puzzles in the social sciences (see Quetelet (1835)). Our empirical work strongly suggests that this variance is not the result of observed or unobserved geographic attributes. This paper presents a model where social interactions create enough covariance across individuals to explain the high cross- city variance of crime rates. This model provides a natural index of social interactions which can compare the degree of social interaction across crimes, across geographic 1units and across time. Our index gives similar results for different data samples and suggests that the amount of social interactions are highest in petty crimes (such as larceny and auto theft), moderate in more serious crimes (assault, burglary and robbery) and almost negligible in murder and rape. The index of social interactions is also applied to non-criminal choices and we find that there is substantial interaction in schooling choice.

Why Do Companies Go Public? An Empirical Analysis

Abstract: This paper empirically analyzes the determinants of an initial public offering (IPO) and the consequences of this decision on a company's investment and financial policy. We compare both the ex ante and the ex post characteristics of IPOs with those of a large sample of privately held companies of similar size. We find that (i) the likelihood of an IPO is positively related to the market-to-book ratio prevailing in the relevant industrial sector and to a company's size, (ii) IPOs are followed by an abnormal reduction in profitability, (iii) the new equity capital raised upon listing is not used to finance subsequent investment and growth, but to reduce leverage, (iv) going public reduces the cost of bank credit; (v) it is often associated by equity sales by controlling shareholders, and is followed by a higher turnover of control than for other companies.

Measuring monetary policy

Abstract: Extending the approach of Bernanke and Blinder (1992), Strongin (1992), and Christano, Eichenbaum, and Evans (1994a, 1994b), we develop and apply a VAR-based methodology for measuring the stance of monetary policy. More specifically, we develop a "demi-structural" VAR approach, which extracts information about monetary policy from data on bank reserves and the federal funds rate but leaves the relationships among the macroeconomic variables in the system unrestricted. The methodology can be used to compare and evaluate existing indicators of monetary policy and also to develop an "optimal" measure (given our framework). Among existing approaches, we find that innovations to the federal funds rate (Bernanke-Blinder) are a good measure of policy innovations during the periods 1965-1979 and 1988-1994; for the period 1979-1994 as a whole, innovations to the orthogonalized component of nonborrowed reserve (Strongin) seems to be the best choice. The new measure of policy stance that we develop conforms well to qualitative indicators of policy such as the Boschen-Mills (1991) index; and innovations to our measure lead to reasonable and precisely estimated dynamic responses by variables such as real GDP and the GDP deflator.

Foreign Direct Investment and Relative Wages: Evidence from MexicoAS Maquiladoras

Abstract: In this paper, we examine the increase in the relative wages of skilled workers in Mexico during the 1980s. We argue that rising wage inequality in Mexico is linked to capital inflows from abroad. The effect of these capital inflows, which correspond to an increase in outsourcing by multinationals from the United States and other Northern countries, is to shift production in Mexico towards relatively skill-intensive goods thereby increasing the relative demand for skilled labor. We study the impact of foreign direct investment (FDI) on the share of skilled labor in total wages in Mexico using state-level data on two-digit industries from the Industrial Census for the period 1975 to 1988. We measure the state- level growth in FDI using data on the regional activities of foreign- owned assembly plants. We find that growth in FDI is positively correlated with the relative demand for skilled labor. In the regions where FDI has been most concentrated, growth in FDI can account for over 50 percent of the increase in the skilled labor share of total wages that occurred during the late 1980s.

Identification and Estimation of Local Average Treatment Effects

Abstract: We investigate conditions sufficient for identification of average treatment effects using instrumental variables. First we show that the existence of valid instruments is not sufficient to identify any meaningful average treatment effect. We then establish that the combination of an instrument and a condition on the relation between the instrument and the participation status is sufficient for identification of a local average treatment effect for those who can be induced to change their participation status by changing the value of the instrument. Finally we derive the probability limit of the standard IV estimator under these conditions. It is seen to be a weighted average of local average treatment effects.

The Forward Discount Anomaly and the Risk Premium: A Survey of Recent Evidence

Abstract: Forward exchange rate unbiasedness is rejected in tests from the current floating exchange rate era. This paper surveys advances in this area since the publication of Hodrick's (1987) survey. It documents that the change in the future exchange rate is generally negatively related to the forward discount. Properties of the expected forward forecast error are reviewed. Issues such as the relation of uncovered interest parity to real interest parity, and the implications of uncovered interest parity for cointegration of various quantities are discussed. The modeling and testing for risk premiums is surveyed. Included in this area are tests of the consumption CAPM, tests of the latent variable model, and portfolio-balance models of risk premiums. General equilibrium models of the risk premium are examined and their empirical implications explored. The survey does not cover the important areas of learning and peso problems, tests of rational expectations based on survey data, or the models of irrational expectations and speculative bubbles.

Some Empirical Evidence on the Effects of Shocks to Monetary Policy on Exchange Rates

Abstract: This paper investigates the effects of shocks to U S monetary policy on exchange rates We consider three measures of these shocks: orthogonalized shocks to the federal funds rate, orthogonalized shocks to the ratio of nonborrowed to total reserves and changes in the Romer and Romer index of monetary policy In sharp contrast to the literature, we find substantial evidence of a link between monetary policy and exchange rates Specifically, according to our results a contractionary shock to U S monetary policy leads to (i) persistent, significant appreciations in U S nominal and real exchange rates and (ii) significant, persistent deviations from uncovered interest rate parity in favor of U S interest rates

How Wide is the Border

Abstract: Failures of the law of one price explain much of the variation in real C.P.I. exchange rates. We use C.P.I. data for U.S. cities and Canadian cities for 14 categories of consumer prices to examine the nature of the deviations from the law of one price. The distance between cities explains a significant amount of the variation in the prices of similar goods in different cities. But, the variation of the price is much higher for two cities located in different countries than for two equidistant cities in the same country. By our most conservative measure, crossing the border adds as much to the volatility of prices as adding 2500 miles between cities.

The Growing Importance of Cognitive Skills in Wage Determination

Abstract: Using data from two longitudinal surveys of American high school seniors, we show that basic cognitive skills had a larger impact on wages for 24-year-old men and women in 1986 than in 1978. For women, the increase in the return to cognitive skills between 1978 and 1986 accounts for all of the increase in the wage premium associated with post-secondary education. We also show that high school seniors' mastery of basic cognitive skills had a much smaller impact on wages two years after graduation than on wages six years after graduation.

Leverage, Investment, and Firm Growth

Abstract: We show that there is a negative relation between leverage and future growth at the firm level and, for diversified firms, at the segment level. Further, this negative relation between leverage and growth holds for firms with low Tobin's q, but not for high-q firms or firms in high-q industries. Therefore, leverage does not reduce growth for firms known to have good investment opportunities, but is negatively related to growth for firms whose growth opportunities are either not recognized by the capital markets or are not sufficiently valuable to overcome the effects of their debt overhang.

Predictable Risk and Returns in Emerging Markets

Abstract: The emergence of new equity markets in Europe, Latin America, Asia, the Mideast and Africa provides a new menu of opportunities for investors. These markets exhibit high expected returns as well as high volatility. Importantly, the low correlations with developed countries' equity markets significantly reduces the unconditional portfolio risk of a world investor. However, standard global asset pricing models, which assume complete integration of capital markets, fail to explain the cross section of average returns in emerging countries. An analysis of the predictability of the returns reveals that emerging market returns are more likely than developed countries to be influenced by local information. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.

Universities as a Source of Commercial Technology: A Detailed Analysis of University Patenting 1965-1988

Abstract: This paper explores changes in university patenting behavior between 1965 and 1988. We show that university patents have increased 15-fold while real university research spending almost tripled. The causes of this increase are unclear, but may include increased focus on commercially relevant technologies, increased industry funding of university research, a 1980 change in federal law that facilitated patenting of results from federally funded research, and the widespread creation of formal technology licensing offices at universities. Up until approximately the mid-1980s, university patents were more highly cited, and were cited by more technologically diverse patents, than a random sample of all patents. This difference is consistent with the notion that university inventions are more important and more basic than the average invention. The differences between the two groups disappeared, however, in the middle part of the 1980s, partly due to a decline in the citation rates for all universities, and partly due to an increasing share of patents going to smaller institutions, whose patents are less highly cited throughout this period. Moreover at both large and small institutions there was a large increase in the fraction of university patents receiving zero citations. Our results suggest that the rate of increase of important patents from universities is much less than the overall rate of increase of university patenting in the period covered by our data.

The Mirage of Fixed Exchange Rates

Abstract: This paper discusses the profound difficulties of maintaining fixed exchange rates in a world of expanding global capital markets. Contrary to popular wisdom, industrialized-country monetary authorities easily have the resources to defend exchange parities against virtually any private speculative attack. But if their commitment to use those resources lacks credibility with markets, the costs to the broader economy of defending an exchange-rate peg can be very high. The dynamic interplay between credibility and commitment is illustrated by the 1992 Swedish and British crises and the 1994-95 Mexican collapse. We also discuss the small number of successful fixers.

Labor Market Institutions and the Distribution of Wages, 1973-1992: A Semiparametric Approach

Abstract: This paper presents a semiparametric procedure to analyze the effects of institutional and labor market factors on recent changes in the U.S. distribution of wages. The effects of these factors are estimated by applying kernel density methods to appropriately 'reweighted' samples. The procedure provides a visually clear representation of where in the density of wages these various factors exert the greatest impact. Using data from the Current Population Survey, we find, as in previous research, that de-unionization and supply and demand shocks were important factors in explaining the rise in wage inequality from 1979 to 1988. We find also compelling visual and quantitative evidence that the decline in the real value of the minimum wage explains a substantial proportion of this increase in wage inequality, particularly for women. We conclude that labor market institutions are as important as supply and demand considerations in explaining changes in the U.S. distribution of wages from 1979 to 1988.

Labor Supply Response to the Earned Income Tax Credit

Abstract: In a series of major expansions starting in 1987, the earned income tax credit (EITC) has become a central part of the federal government's anti-poverty strategy. In this paper, we examine the impact of the Tax Reform Act of 1986 (TRA86), which included an expansion of the EITC, on labor force participation and hours of work. The expansion of the credit affected an easily identifiable group, single women with children, but is predicted to have had no effect on another group, single women without children. Other features of TRA86, such as the increase in the value of dependent exemptions and the large increase in the standard deduction for head of household filers, are predicted by economic theory to have reinforced the impact of the EITC on the relative labor supply outcomes of single women with and without children. We therefore compare the change in labor supply of single women with children to the change in labor supply of single women without children. We find that between 1984-1986 and 1988-1989 single women with children increased their labor force participation by 1.4 percentage points (from a base of 73.1 percent) relative to single women without children. We explore a number of possible explanations for this finding and conclude that the 1987 expansion of the EITC and the other provisions of TRA86 are the most likely explanations. We find no effect of the EITC expansion on the hours of work of single women with children who were already in the labor force. Compared to other elements of the welfare system, the EITC appears to produce little distortion of work incentives.

Risk Taking by Mutual Funds as a Response to Incentives

Abstract: This paper examines the agency conflict between mutual fund investors and mutual fund companies. Investors would like the fund company to use its judgement to maximize risk-adjusted fund returns. A fund company, however, in its desire to maximize its value as a concern has an incentive to take actions which increase the inflow of investment. We use a semiparametric model to estimate the shape of the flow-performance relationship for a sample of growth and growth and income funds observed over the 1982-1992 period. The shape of the flow-performance relationship creates incentives for fund managers to increase or decrease the riskiness of the fund which are dependent on the fund's year-to-date return. Using a new dataset of mutual fund portfolios which includes equity portfolio holdings for September and December of the same year, we show that mutual funds do alter their portfolio riskiness between September and December in a manner consistent with these risk incentives.

Using Electoral Cycles in Police Hiring to Estimate the Effect of Police on Crime

Abstract: Previous empirical studies have typically uncovered little evidence that police reduce crime. One problem with those studies is a failure to adequately deal with the simultaneity between police and crime: while police may or may not reduce crime, there is little doubt that expenditures on police forces are an increasing function of the crime rate. In this study, the timing of mayoral and gubernatorial elections is used to identify the effect of police on crime. This paper first demonstrates that increases in the size of police forces disproportionately occur in mayoral and gubernatorial election years, a relationship that had previously gone undocumented. After controlling for changes in government spending on other social programs, there is little reason to think that elections will be otherwise correlated with crime, making elections ideal instruments. Using a panel of large U.S. cities from 1970-1992, police are shown to reduce crime for six of the seven crime categories examined. Each additional police officer is estimated to eliminate eight to ten serious crimes. Existing estimates of the costs of crime suggest that the social benefit of reduced crime is approximately $100,000 per officer per year, implying that the current number of police is below the optimal level.

The Growth of Nations

Abstract: AVERAGE INCOMES in the world's richest countries are more than ten times as high as in the world's poorest countries. It is apparent to anyone who travels the world that these large differences in income lead to large differences in the quality of life. Less apparent are the reasons for these differences. What is it about the United States, Japan, and Germany that makes these countries so much richer than India, Indonesia, and Nigeria? How can the rich countries be sure to maintain their high standard of living? What can the poor countries do to join the club? After many years of neglect, these questions are again at the center of macroeconomic research and teaching. Long-run growth is now widely viewed to be at least as important as short-run fluctuations. Moreover, growth is not just important. It is also a topic about which macroeconomists, with their crude aggregate models, have something useful to say. My goal here is to assess what we now know about economic growth. The scope of this paper is selective and, to some extent, idiosyncratic. The study of growth has itself grown so rapidly in recent years that it would take an entire book to discuss the field thoroughly.' In this paper, I do not try to lay out the many different views in the large literature on economic growth. Instead, I try to present my own views, as cogently as I can, on what we know about the growth of nations.

Does Head Start Make a Difference

Abstract: Data from a national sample of children are used to investigate the effects of participation in Head Start on a range of child outcomes. In order to control for selection into the program comparisons are drawn between siblings and also between the relative benefits associated with attending Head Start on one hand and other preschools on the other. There are large and significant gains associated with attending Head Start as measured by test scores. This is true relative to children who attend no preschool and also relative to those who attend other preschools. There are also important racial differences in these benefits. Both Whites and African-Americans experience initial gains in test scores as a result of participation in Head Start. But among African-Americans the gains are quickly lost whereas for Whites the gains persist well into adulthood. As a result perhaps Head Start significantly reduces the probability that a White child will repeat a grade but has no effect on grade repetition among African-American children. In contrast relative to children who attend no preschool both Whites and African-Americans gain greater access to preventive health services as measured by immunization rates although children who attend other preschools enjoy similar benefits. (authors)