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325. Bruce E. Hansen, "Inference in TAR Models" (revised 9/97: 314 Kb, Adobe Acrobat format. GAUSS programs and data for this paper are downloadable in .ZIP format (14 Kb).
Abstract : A distribution theory is developed for least squares estimates of the threshold in threshold autoregressive (TAR) models. We find that if we let the threshold effect (the difference in slopes between the two regimes) get small as the sample size increases, then the asymptotic distribution of the threshold estimator is free of nuisance parameters (up to scale). Similarly, the likelihood ratio statistic for testing hypotheses concerning the unknown threshold is asymptotically free of nuisance parameters. These asymptotic distributions are non-standard, but are available in closed form so critical values are readily available. To illustrate this theory, we report an application to the U.S. unemployment rate. We find statistically significant threshold effects.
323. Joseph Quinn, "Entitlements and the Federal Budget" (2/96: 83 Kb, Adobe Acrobat format. Figures available from the author. Published by National Institute on Aging, Washington, 1996).
322. Jill Quadagno (Florida State University) and Joseph Quinn, "Does Social Security Discourage Work?" (6/95: 49 Kb, Adobe Acrobat format. Figures available from the author. Published in Social Security in the 21st Century, E. Kingson and J. Schulz, eds., 1997, Oxford University Press, 127-146).
321. John Barkoulas, Christopher F. Baum, and Mustafa Caglayan, "Fractional Monetary Dynamics" (revised 01/98: 182 Kb, Adobe Acrobat format. Published in Applied Economics, 1999, 31, 1393-1400.)
Abstract : We test for fractional dynamics in U.S. monetary series, their various formulations and components, and velocity series. Using the spectral regression method, we find evidence of a fractional exponent in the differencing process of the monetary series (both simple-sum and Divisia indices), in their components (with the exception of demand deposits, savings deposits, overnight repurchase agreements, and term repurchase agreements), and the monetary base and money multipliers. No evidence of fractional behavior is found in the velocity series. Granger's (1980) aggregation hypothesis is evaluated and implications of the presence of fractional monetary dynamics are drawn.
320. John Barkoulas, Christopher F. Baum, Joseph Onochie (Baruch College), "A Nonparametric Investigation of the 90-Day T-Bill Rate" (rev. 5/97: 90 Kb, Adobe Acrobat format). Published in Review of Financial Economics, 6:2, 187-198.
Abstract : We employ a nonlinear, nonparametric method to model the stochastic behavior of changes in the 90-day U.S. T-bill rate. The estimation technique is locally weighted regression (LWR), a nearest-neighbor method, and the forecasting criteria are the root mean square error (RMSE) and mean absolute deviation (MAD) measures. We compare the forecasting performance of the nonparametric fit to the performance of two benchmark linear models: an autoregressive model and a random-walk-with-drift model. The nonparametric fit results in significant improvements in forecasting accuracy as compared to benchmark linear models both in-sample and out-of-sample, thus establishing the presence of substantial nonlinear mean predictability of changes in the 90-day T-bill rate.
319. Bruce E. Hansen, "Sample Splitting and Threshold Estimation" (revised 4/98: 360 Kb, Adobe Acrobat format. Programs and data for this paper are downloadable in .ZIP format (14 Kb).
Abstract : Threshold models have a wide variety of applications in economics. Direct applications include models of separating and multiple equilibria. Other applications include empirical sample splitting when the sample split is based on a continuously-distributed variable such as firm size. In addition, threshold models may be used as a parsimonious strategy for non-parametric function estimation. For example, the threshold autoregressive model (TAR) is popular in the non-linear time series literature.
Threshold models also emerge as special cases of more complex statistical frameworks, such as mixture models, switching models, Markov switching models, and smooth transition threshold models. It may be important to understand the statistical properties of threshold models as a preliminary step in the development of statistical tools to handle these more complicated structures.
Despite the large number of potential applications, the statistical theory of threshold estimation is undeveloped. The previous literature has demonstrated that threshold estimates are super-consistent, but a distribution theory useful for testing and inference has yet to be provided.
This paper develops a statistical theory for threshold estimation in the regression context. We allow for either cross-section or time series observations. Least squares estimation of the regression parameters is considered. An asymptotic distribution theory for the regression estimates (the threshold and the regression slopes) is developed. It is found that the distribution of the threshold estimate is non-standard. A method to construct asymptotic confidence intervals is developed by inverting the likelihood ratio statistic. It is shown that this yields asymptotically conservative confidence regions. Monte Carlo simulations are presented to assess the accuracy of the asymptotic approximations. The empirical relevance of the theory is illustrated through an application to the multiple equilibria growth model of Durlauf and Johnson (1995).
318. Salih Gurcan Gülen, "Is OPEC a Cartel? Evidence from Cointegration and Causality Tests" (5/96: 215 Kb, Adobe Acrobat format) An abridged version of this paper has been published in The Energy Journal, Vol. 17, 2:43-57.
Abstract : The energy shocks of the 1970's had significant effects on the global economy. Were they engineered by an effective cartel of OPEC members acting to share the market by controlling output and influencing market prices? If OPEC was an effective cartel sharing the market among its members, there would be a long-run relationship between each member's individual production and total OPEC output. One would also expect OPEC's production to significantly affect the market price of oil as the organization is often accused of curbing production in order to raise prices. These implications of cartel behavior are tested via cointegration and causality tests. The likely effects of regime changes are dealt with using techniques developed by Perron (1989). There is evidence of output coordination among some members of the organization, especially in the output rationing era (1982-93). This is also the only period in which the causality from OPEC production to the price of oil is statistically significant. Overall, the evidence suggests that OPEC did act as a cartel in the 1980's in order to maintain prices, while it simply took advantage of market conditions in the 1970's and did not have to restrain output.
317. John Barkoulas, Christopher F. Baum, "Fractional Differencing Modeling and Forecasting of Eurocurrency Deposit Rates" (rev. 10/96: 75 Kb, Adobe Acrobat format. Published in Journal of Financial Research, Fall 1997, 20:3, 355-372).
Abstract: We investigate the low frequency properties of three- and six-month rates for Eurocurrency deposits denominated in eight major currencies with specific emphasis on fractional dynamics. Using the fractional integration testing procedure suggested by Geweke and Porter-Hudak (1983), we find that several of the Eurocurrency deposit rates are fractionally integrated processes with long memory. These findings have important implications for econometric modeling, forecasting, and cointegration testing of Eurocurrency rates.
316. James E. Anderson, Will Martin (World Bank), "The Welfare Analysis of Fiscal Policy: A Simple Unified Account" (4/96: 99 Kb, Adobe Acrobat format)
Abstract : A simple general equilibrium model of an economy with distortionary taxes and public goods is used to extend, unify and clean up the welfare analysis of changes in taxation, redistribution and the provision of public goods. We clarify the distinction between compensation and money metric measures of the welfare impact of fiscal changes and show that the equivalent variation measure dominates other measures. We provide an integrated approach to marginal tax and public good changes when public goods have real resource costs and must be financed by distortionary taxation using the concepts of the marginal cost of funds, the fiscal price of public goods and the virtual price of public goods. Here too, the compensation version of these concepts dominates the money metric version.
Abstract: DeGennaro, Kunkel, and Lee (1994) studied the long run dynamics of a system of long term interest rates of five industrialized countries by means of sophisticated cointegration methods. They found little evidence in support of the cointegration hypothesis, thus concluding that a separate set of fundamentals drives the dynamics of each of the individual long term interest rate series. In this study, we extend their analysis by exploring the possibility of very slow mean reverting dynamics (fractional cointegration) in the system of the five long term interest rates. We use the GPH test as our testing methodology for fractional integration and cointegration. Through rigorous investigation of the full system of the five long term interest rate series and its various subsystems, we provide evidence that the error correction term follows a fractionally integrated process with long memory, that is, it is mean reverting, though not covariance stationary. Despite significant persistence in the short run, a shock to the system of long term interest rates eventually dissipates so that an equilibrium relationship prevails in the long run.
(Previously titled "Testing for Fractal Structure in Stock Returns")
Abstract: This paper investigates the presence of fractal dynamics in stock returns. We improve upon existing literature in two ways: i) instead of rescaled-range analysis, we use the more efficient semi-nonparametric procedure suggested by Geweke and Porter-Hudak (GPH, 1983), and ii) to ensure robustness, we apply the GPH test to a variety of aggregate and sectoral stock indices and individual companies' stock returns series at both daily and monthly frequencies. Our results indicate that fractal structure is not exhibited by stock indices, but it may characterize the behavior of some individual stock returns series.
Abstract: We employ a nonlinear, nonparametric method to model the stochastic behavior of changes in several short and long term U.S. interest rates. We apply a nonlinear autoregression to the series using the locally weighted regression (LWR) estimation method, a nearest-neighbor method, and evaluate the forecasting performance with a measure of root mean square error. We compare the forecasting performance of the nonparametric fit to the performance of two benchmark linear models: an autoregressive model and a random-walk-with-drift model. The nonparametric model exhibits greater out-of-sample forecast accuracy than that of the linear predictors for most U.S. interest rate series. The improvements in forecasting accuracy are statistically significant and robust. This evidence establishes the presence of significant nonlinear mean predictability in U.S. interest rates, as well as the usefulness of the LWR method as a modeling strategy for these benchmark series.
Abstract: It is often argued that monetary instability reduces the informational content of market signals and thereby hinders the efficient allocation of investment. In this paper we use a signal extraction framework to give empirical content to this idea. In particular, we show why this framework predicts that, as monetary uncertainty decreases, the cross-sectional distribution of investment widens. We then explore this hypothesis using panel data information for UK companies over twenty years. Our data generally support the view that monetary instability may affect investment allocation through its effect on the predictability of prices.
Abstract: We re-examine Sephton and Larsen's (1991) conclusion that cointegration-based tests for market efficiency suffer from temporal instability. We improve upon their research by i) including a drift term in the vector error correction model (VECM) in the Johansen procedure, ii) correcting the likelihood ratio test statistic for finite-sample bias, and iii) fitting the model over longer data sets. We show that instability of the Johansen cointegration tests mostly disappears after accounting for these two factors. The evidence is even more stable in favor of no cointegration when we apply our analysis to longer data sets.
Abstract: In the past decade, we have seen the development of a new set of tests for structural change of unknown timing in regression models, most notably the SupF statistic of Andrews (1993), the ExpF and AveF statistics of Andrews-Ploberger (1994), and the L statistic of Nyblom (1989). The distribution theory used for these tests is primarily asymptotic, and has been derived under the maintained assumption that the regressors are stationary. This excludes structural change in the marginal distribution of the regressors. As a result, these tests technically cannot discriminate between structural change in the conditional and marginal distributions. This paper attempts to remedy this deficiency by deriving the large sample distributions of the test statistics allowing for structural change in the marginal distribution of the regressors. We find that the asymptotic distributions of the SupF, ExpF, AveF and L statistics are not invariant to structural change in the regressors. To solve the size problem, we introduce a 'fixed regressor bootstrap' which achieves the first-order asymptotic distribution, and appears to possess reasonable size properties in small samples. Our bootstrap theory allows for arbitrary structural change in the regressors, including structural shifts, polynomial trends, and exogenous stochastic trends. It allows for lagged dependent variables and heteroskedastic error processes.
"Effective Protection Redux" (9/95: 83Kb, Adobe Acrobat format; published, Journal of International Economics, 1998, 44:21-44)Abstract: This paper rehabilitates effective protection. In general equilibrium, the usual definition (the percentage change in value added per unit induced by the tariff structure) corresponds to no economically interesting magnitude. The effective rate of protection for sector j is defined here as the uniform tariff which is equivalent to the actual differentiated tariff structure in its effect on the rents to residual claimants in sector j. This definition applies to general as well as partial equilibrium economic structures, has obvious relevance for political economy models and seems to correspond to the motivation for the early effective protection literature. Like the earlier effective rate formula, the concept is operational using the widely available set of Computable General Equilibrium (CGE) models. An example is provided for the US economy. The numerical results for the old and new concepts are not significantly correlated.
"A General Equilibrium Spatial Model of Housing Quality and Quantity" (8/95: 264Kb, Adobe Acrobat format)
Abstract: This paper examines the properties of stationary-state general equilibrium in a monocentric city with durable housing. On the demand side, identical households choose location, housing quality and quantity (floor area), and other goods. On the supply side, developers choose the structural density and time path of quality (which depends on construction quality and maintenance) of buildings. Under a certain set of assumptions, existence and uniqueness of equilibrium are proved, and its comparative static/dynamic properties are determined.
"Is Earnings Inequality Also Rising in Other Industrialized Countries ?--the Role of Institutional Constraints" (8/95: 66Kb, Adobe Acrobat format)"Recent Developments in the Bottleneck Model" (8/95)"Self-Financing of Congestible Facilities in a Growing Economy" (6/95: 99Kb, Adobe Acrobat format)"Does Employee Ownership Improve Incentives for Efforts?" (8/95: 462Kb, Adobe Acrobat format)
Abstract: This paper provides a theoretical framework to analyze workers' incentives under different ownership. It shows that the workers' effort and expected income are higher and the monitoring intensity is lower in the employee-owned firm than in the capitalist firm. Unlike in previous models, the advantage of employee ownership here does not depend on the size of the firm. It also shows that the advantage of employee ownership increases as workers' reservation wage decreases, the monitoring cost and productivity uncertainty increases. Finally, it discusses the relevance of the theory to employee stock-ownership program (ESOP) and profit sharing.
"Are Brokers' Commission Rates on Home Sales Too High? A Conceptual Analysis" (4/95: 248Kb, Adobe Acrobat format)Abstract: Many people believe that prevailing commission rates for residential real estate brokers are "too high" but do not offer a formal model. This paper presents a general equilibrium model of the housing market in which real estate brokers serve as matching intermediaries. We use this model to construct an illustrative example which is "calibrated" using data representative of a typical housing market.
"A Filtering Model with Steady-State Housing" (2/95: 231Kb, Adobe Acrobat format)Abstract: This paper presents a filtering model of the housing market which is similar to Sweeney's (1974b), except that the maintenance technology is such that housing can be maintained at a constant quality level as well as downgraded, and population at each income level grows continuously over time. In equilibrium, at each moment of time, some housing is allowed to deteriorate in quality, and other housing is maintained in a steady-state interval of qualities.
"Rethinking the Univariate Approach to Unit Root Testing: Using Covariates to Increase Power" (5/95: now published in Econometric Theory, 1995, 11:1148-1172)Abstract: In the context of testing for a unit root in a univariate time series, the convention is to ignore information in related time series. This paper shows that this convention is quite costly, as large power gains can be achieved by including correlated stationary covariates in the regression equation. The paper derives the asymptotic distribution of ordinary least squares (OLS) estimates of the largest autoregressive root and its t statistic. The asymptotic distribution is not the conventional ''Dickey-Fuller'' distribution, but a convex combination of the Dickey-Fuller distribution and the standard normal, the mixture depending on the correlation between the equation error and the regression covariates. The local asymptotic power functions associated with these test statistics suggest enormous gains over the conventional unit root tests. A simulation study and empirical application illustrate the potential of the new approach.