
- •Preface
- •Part IV. Basic Single Equation Analysis
- •Chapter 18. Basic Regression Analysis
- •Equation Objects
- •Specifying an Equation in EViews
- •Estimating an Equation in EViews
- •Equation Output
- •Working with Equations
- •Estimation Problems
- •References
- •Chapter 19. Additional Regression Tools
- •Special Equation Expressions
- •Robust Standard Errors
- •Weighted Least Squares
- •Nonlinear Least Squares
- •Stepwise Least Squares Regression
- •References
- •Chapter 20. Instrumental Variables and GMM
- •Background
- •Two-stage Least Squares
- •Nonlinear Two-stage Least Squares
- •Limited Information Maximum Likelihood and K-Class Estimation
- •Generalized Method of Moments
- •IV Diagnostics and Tests
- •References
- •Chapter 21. Time Series Regression
- •Serial Correlation Theory
- •Testing for Serial Correlation
- •Estimating AR Models
- •ARIMA Theory
- •Estimating ARIMA Models
- •ARMA Equation Diagnostics
- •References
- •Chapter 22. Forecasting from an Equation
- •Forecasting from Equations in EViews
- •An Illustration
- •Forecast Basics
- •Forecasts with Lagged Dependent Variables
- •Forecasting with ARMA Errors
- •Forecasting from Equations with Expressions
- •Forecasting with Nonlinear and PDL Specifications
- •References
- •Chapter 23. Specification and Diagnostic Tests
- •Background
- •Coefficient Diagnostics
- •Residual Diagnostics
- •Stability Diagnostics
- •Applications
- •References
- •Part V. Advanced Single Equation Analysis
- •Chapter 24. ARCH and GARCH Estimation
- •Basic ARCH Specifications
- •Estimating ARCH Models in EViews
- •Working with ARCH Models
- •Additional ARCH Models
- •Examples
- •References
- •Chapter 25. Cointegrating Regression
- •Background
- •Estimating a Cointegrating Regression
- •Testing for Cointegration
- •Working with an Equation
- •References
- •Binary Dependent Variable Models
- •Ordered Dependent Variable Models
- •Censored Regression Models
- •Truncated Regression Models
- •Count Models
- •Technical Notes
- •References
- •Chapter 27. Generalized Linear Models
- •Overview
- •How to Estimate a GLM in EViews
- •Examples
- •Working with a GLM Equation
- •Technical Details
- •References
- •Chapter 28. Quantile Regression
- •Estimating Quantile Regression in EViews
- •Views and Procedures
- •Background
- •References
- •Chapter 29. The Log Likelihood (LogL) Object
- •Overview
- •Specification
- •Estimation
- •LogL Views
- •LogL Procs
- •Troubleshooting
- •Limitations
- •Examples
- •References
- •Part VI. Advanced Univariate Analysis
- •Chapter 30. Univariate Time Series Analysis
- •Unit Root Testing
- •Panel Unit Root Test
- •Variance Ratio Test
- •BDS Independence Test
- •References
- •Part VII. Multiple Equation Analysis
- •Chapter 31. System Estimation
- •Background
- •System Estimation Methods
- •How to Create and Specify a System
- •Working With Systems
- •Technical Discussion
- •References
- •Vector Autoregressions (VARs)
- •Estimating a VAR in EViews
- •VAR Estimation Output
- •Views and Procs of a VAR
- •Structural (Identified) VARs
- •Vector Error Correction (VEC) Models
- •A Note on Version Compatibility
- •References
- •Chapter 33. State Space Models and the Kalman Filter
- •Background
- •Specifying a State Space Model in EViews
- •Working with the State Space
- •Converting from Version 3 Sspace
- •Technical Discussion
- •References
- •Chapter 34. Models
- •Overview
- •An Example Model
- •Building a Model
- •Working with the Model Structure
- •Specifying Scenarios
- •Using Add Factors
- •Solving the Model
- •Working with the Model Data
- •References
- •Part VIII. Panel and Pooled Data
- •Chapter 35. Pooled Time Series, Cross-Section Data
- •The Pool Workfile
- •The Pool Object
- •Pooled Data
- •Setting up a Pool Workfile
- •Working with Pooled Data
- •Pooled Estimation
- •References
- •Chapter 36. Working with Panel Data
- •Structuring a Panel Workfile
- •Panel Workfile Display
- •Panel Workfile Information
- •Working with Panel Data
- •Basic Panel Analysis
- •References
- •Chapter 37. Panel Estimation
- •Estimating a Panel Equation
- •Panel Estimation Examples
- •Panel Equation Testing
- •Estimation Background
- •References
- •Part IX. Advanced Multivariate Analysis
- •Chapter 38. Cointegration Testing
- •Johansen Cointegration Test
- •Single-Equation Cointegration Tests
- •Panel Cointegration Testing
- •References
- •Chapter 39. Factor Analysis
- •Creating a Factor Object
- •Rotating Factors
- •Estimating Scores
- •Factor Views
- •Factor Procedures
- •Factor Data Members
- •An Example
- •Background
- •References
- •Appendix B. Estimation and Solution Options
- •Setting Estimation Options
- •Optimization Algorithms
- •Nonlinear Equation Solution Methods
- •References
- •Appendix C. Gradients and Derivatives
- •Gradients
- •Derivatives
- •References
- •Appendix D. Information Criteria
- •Definitions
- •Using Information Criteria as a Guide to Model Selection
- •References
- •Appendix E. Long-run Covariance Estimation
- •Technical Discussion
- •Kernel Function Properties
- •References
- •Index
- •Symbols
- •Numerics

352—Chapter 28. Quantile Regression
Symmetry Testing
Newey and Powell (1987) construct a test of the less restrictive hypothesis of symmetry, for asymmetric least squares estimators, but the approach may easily be applied to the quantile regression case.
The premise of the Newey and Powell test is that if the distribution of metric, then:
b--------------------------------------(t) + b(1 – t) |
= b(1 § 2) |
2 |
|
Y given X is sym-
(28.36)
We may evaluate this restriction using Wald tests on the quantile process. Suppose that there are an odd number, K , of sets of estimated coefficients ordered by tk . The middle
value t(K + 1) § 2 is assumed to be equal to 0.5, and the remaining t are symmetric around 0.5, with tj = 1 – tK – j + 1 , for j = 1, º, (K – 1) § 2 . Then the Newey and Powell test
null is the joint hypothesis that:
H0: |
b(tj) + b(tK – j – 1) |
= b(1 § 2) |
(28.37) |
----------------------------------------------- |
|||
|
2 |
|
|
for j = 1, º, (K – 1) § 2 .
The Wald test formed for this null is zero under the null hypothesis of symmetry. The null has p(K – 1) § 2 restrictions, so the Wald statistic is distributed as a x2p(K – 1) § 2 . Newey and Powell point out that if it is known a priori that the errors are i.i.d., but possibly asymmetric, one can restrict the null to only examine the restriction for the intercept. This restricted null imposes only (K – 1) § 2 restrictions on the process coefficients.
References
Barrodale I. and F. D. K. Roberts (1974). “Solution of an Overdetermined System of Equations in the l1 Norm,” Communications of the ACM, 17(6), 319-320.
Bassett, Gilbert Jr. and Roger Koenker (1982). “An Empirical Quantile Function for Linear Models with i.i.d. Errors,” Journal of the American Statistical Association, 77(378), 407-415.
Bofinger, E. (1975). “Estimation of a Density Function Using Order Statistics,” Australian Journal of Statistics, 17, 1-7.
Buchinsky, M. (1995). “Estimating the Asymptotic Covariance Matrix for Quantile Regression Models: A Monte Carlo Study,” Journal of Econometrics, 68, 303-338.
Chamberlain, Gary (1994). “Quantile Regression, Censoring and the Structure of Wages,” in Advances in Econometrics, Christopher Sims, ed., New York: Elsevier, 171-209.
Falk, Michael (1986). “On the Estimation of the Quantile Density Function,” Statistics & Probability Letters, 4, 69-73.
Hall, Peter and Simon J. Sheather, “On the Distribution of the Studentized Quantile,” Journal of the Royal Statistical Society, Series B, 50(3), 381-391.
He, Xuming and Feifang Hu (2002). “Markov Chain Marginal Bootstrap,” Journal of the American Statistical Association, 97(459), 783-795.

References—353
Hendricks, Wallace and Roger Koenker (1992). “Hierarchical Spline Models for Conditional Quantiles and the Demand for Electricity,” Journal of the American Statistical Association, 87(417), 58-68.
Jones, M. C. (1992). “Estimating Densities, Quantiles, Quantile Densities and Density Quantiles,” Annals of the Institute of Statistical Mathematics, 44(4), 721-727.
Kocherginsky, Masha, Xuming He, and Yunming Mu (2005). “Practical Confidence Intervals for Regression Quantiles,” Journal of Computational and Graphical Statistics, 14(1), 41-55.
Koenker, Roger (1994), “Confidence Intervals for Regression Quantiles,” in Asymptotic Statistics, P. Mandl and M. Huskova, eds., New York: Springer-Verlag, 349-359.
Koenker, Roger (2005). Quantile Regression. New York: Cambridge University Press.
Koenker, Roger and Gilbert Bassett, Jr. (1978). “Regression Quantiles,” Econometrica, 46(1), 33-50.
Koenker, Roger and Gilbert Bassett, Jr. (1982a). “Robust Tests for Heteroskedasticity Based on Regression Quantiles,” Econometrica, 50(1), 43-62.
Koenker, Roger and Gilbert Bassett, Jr. (1982b). “Tests of Linear Hypotheses and l1 Estimation,” Econometrica, 50(6), 1577-1584.
Koenker, Roger W. and Vasco D’Orey (1987). “Algorithm AS 229: Computing Regression Quantiles,”
Applied Statistics, 36(3), 383-393.
Koenker, Roger and Kevin F. Hallock (2001). “Quantile Regression,” Journal of Economic Perspectives, 15(4), 143-156.
Koenker, Roger and Jose A. F. Machado (1999). “Goodness of Fit and Related Inference Processes for Quantile Regression,” Journal of the American Statistical Association, 94(448), 1296-1310.
Newey, Whitney K., and James L. Powell (1987). “Asymmetric Least Squares Estimation,” Econometrica, 55(4), 819-847.
Portnoy, Stephen and Roger Koenker (1997), “The Gaussian Hare and the Laplacian Tortoise: Computability of Squared-Error versus Absolute-Error Estimators,” Statistical Science, 12(4), 279-300.
Powell, J. (1984). “Least Absolute Deviations Estimation for the Censored Regression Model,” Journal of Econometrics, 25, 303-325.
Powell, J. (1986). “Censored Regression Quantiles,” Journal of Econometrics, 32, 143-155.
Powell, J. (1989). “Estimation of Monotonic Regression Models Under Quantile Restrictions,” in Nonparametric and Semiparametric Methods in Econometrics, W. Barnett, J. Powell, and G. Tauchen, eds., Cambridge: Cambridge University Press.
Siddiqui, M. M. (1960). “Distribution of Quantiles in Samples from a Bivariate Population,” Journal of Research of the National Bureau of Standards–B, 64(3), 145-150.
Silverman, B. W. (1986). Density Estimation for Statistics and Data Analysis, London: Chapman & Hall.
Welsh, A. H. (1988). “Asymptotically Efficient Estimation of the Sparsity Function at a Point,” Statistics & Probability Letters, 6, 427-432.

354—Chapter 28. Quantile Regression