A convenient test of functional form for pooled econometric models

This paper demonstrates a parametric test of specification that can be used in validating econometric models employing pooled time series and cross-section data with fixed effects. This Lagrange multiplier test allows for the simultaneous testing of proper model functional form and the presence of nonspherical disturbances, using a combination of the Box-Cox transformation, the double-length regression of Davidson and MacKinnon, and the Bonferroni inducedt-test. Testing procedures are demonstrated using a model of long distance telephone demand in the United States. The illustrative model used is representative of models filed as direct testimony by telephone companies in administrative law proceedings, which usually require rigorous model validation and defenses of model results in a formal hearing room setting. The tests presented in this paper are useful to a wide variety of researchers who use pooled econometric models with fixed effects in their work.     

基于动态计量模型的青海省域经济增长实证分析

青海作为西部大开发中增长相对较慢的省份，其经济增长的问题与切入点如何，文章运用Eviews5．0统计软件，根据协整理论将对拉动经济增长的消费、投资、进出口三大马车与青海省的经济增长进行了实证研究。结果表明加快与社会主义市场经济相适应的各种制度的改革，引导消费，扩大需求，继续加大投资是当前加快青海省经济增长的着眼点。     

Consumer allocation models: Choice of functional form

The functional form of consumer allocation models should be able to satisfy theoretical properties derived from the theory of consumer demand. The paper sketches four approaches that meet this condition. Of course, also empirical performance matters. Next to naive goodness-of-fit comparison, non-nested hypothesis testing can be employed. The latter technique is applied to a comparison of four versions of differential demand systems: the Rotterdam system, a version of the Almost Ideal Demand (AID) system, the CBS system and the NBR system. These systems are artificially nested in a more general model using scalar weights in contrast to Barten and McAleer (1991) who use matrix weights for this purpose. Annual data over the period 1921–1981 for The Netherlands for four major groups of consumer expenditure have been used for the empirical application. The CBS system dominates the others.     

Advertising in consumer allocation models: choice of functional form

This study investigates the empirical performance of four different functional forms for advertising-augmented consumer allocation models. The investigation is carried out within the context of the UK alcoholic drinks markets. The aims of the study are twofold: (i) to assess which of the four functional forms provides the best explanation of the data and may serve, therefore, as the most suitable framework for investigating advertising effects in these markets; and (ii) to consider whether the findings with regard to advertising effects are robust and consistent across model specifications. Advertising is found to have had no significant effect upon the ‘product composition’ or ‘level’ of total alcoholic drink consumption in the UK over the period from 1964 to 1996, and this result is robust with respect to variations in the specification of functional form. The consumption of alcoholic drink is affected by relative prices, total consumer budgeted expenditures and, to some extent, by autonomous shifts in tastes. The balance of the evidence from tests for functional form appeared to favour the Almost Ideal Demand system as a framework for investigating the influence of advertising and other factors on drink consumption.     

基于动态计量模型的青海省域经济增长实证分析

青海作为西部大开发中增长相对较慢的省份,其经济增长的问题与切入点如何,文章运用Eviews5.0统计软件,根据协整理论将对拉动经济增长的消费、投资、进出口三大马车与青海省的经济增长进行了实证研究.结果表明加快与社会主义市场经济相适应的各种制度的改革,引导消费,扩大需求,继续加大投资是当前加快青海省经济增长的着眼点.     

Choice of the empirical definition of zero in the translog multiproduct cost functional form

The translog cost function is valuable to researchers for empirical analysis in themodelling of indirect cost and profit functions. A flaw of the functional form is in themodelling of zero output values. This study examined the impacts of empirical definition of zero output values on price elasticities, economies of scope and scale, using the translog cost function. Estimation of a system of cost and factor share equations with regularity condition imposed was conducted. Results show that the choice of default values affects policy recommendations.     

Relationships among estimators of triangular econometric models

Estimators for triangular models where one endogenous variable may be dichotomous are compared. The selection bias correction method utilized in the simultaneous probit model is applied to standard simultaneous equations models. The resulting estimator is shown to be equivalent to 2SLS in some cases and provides a Hausman (1978) test of endogeneity. Also, other comparisons of estimators are made.     

Nonparametric estimation and hypothesis testing in econometric models

In this paper we systematically review and develop nonparametric estimation and testing techniques in the context of econometric models. The results are discussed under the settings of regression model and kernel estimation, although as indicated in the paper these results can go through for other econometric models and for the nearest neighbor estimation. A nontechnical survey of the asymptotic properties of kernel regression estimation is also presented. The technique described in the paper are useful for the empirical analysis of the economic relations whose true functional forms are usually unknown.     

Improving the econometric precision of regulatory models

Regulatory regimes often attempt to introduce quasi-competitive pressures by undertaking comparative efficiency assessments between the regulated companies and setting company-specific cost reduction targets based on those comparisons. The UK water industry is one example of such a regime—indeed, it has emphasized the importance of maintaining the number of independent companies in order to preserve the robustness of the modeling. For example, in 2007, the Competition Commission considered whether the merger between Mid Kent Water and South East Water might prejudice the ability of the regulator (Ofwat) to make comparisons across water companies for the purposes of assessing performance and setting price controls. In this paper, we examine this issue and provide specific recommendations to regulators. Our cross-sectional results show that the impact of this merger is not significant. We demonstrate that joint estimation of all the sub-models using the ‘seemingly unrelated regression’ (SUR) procedure in a cross-section and/or panel data framework can dramatically improve the accuracy of the modeling. Moreover, the merger does not affect the confidence intervals significantly under such approaches, which still remain far superior to those under Ofwat’s cross-sectional approach. Based on these results, we recommend that Ofwat and other regulators adopt SUR and/or panel data analysis and thereby reduce their reliance on having sufficient numbers of independent companies.     

The Southampton econometric model building unit : Some lessons learned

This paper draws on the author's experience as a research fellow on the Southampton Econometric Model Building Unit in suggesting that there is a case for large-scale, structural, disaggregated econometric models. This is particularly so if, like SEMBU, the aim is to improve both economic theory and economic policy advice rather than simply to forecast actual futures. It is argued that for such an approach to model building to be successful, funding agencies should adopt a long-term view and the Central Statistical Office and other data generating bodies should become much more closely involved with the model-building unit. This latter cooperation could prove mutually beneficial.     

A dynamic econometric model of Thailand manufacturing energy demand

The purpose of this article is to employ the dynamic translog framework to model inter-factor and inter-fuel energy demand for the Thai manufacturing sector. The Denny et al. (1981) and Lynk (1989) framework, which proposes a dynamic adjustment for capital stock is employed to motivate the estimated of factor demand and fuel share equations. Three factors: energy, labour and capital; and five fuel types: fuel oil, diesel oil, liquified petroleum gas (LPG), electricity, and coal and lignite; are examined. Regression diagnostics support the empirical specification. Numerous factor and fuel substitution possibilities are identified, with some policy implications described.     

Fiscal devaluation and real exchange rates in the Euro area: Some econometric insights

We explore whether a fiscal devaluation, that is, a reduction in employers’ social security contributions and an increase in value added tax, affects two indicators of bilateral real exchange rates in the euro area: one based on unit labor costs, and another based on consumer prices. We find that, in the short term, cuts in employers’ contributions depreciate real exchange rates based on unit labor costs, while value added tax hikes appreciate real exchange rates based on consumer prices. In the long run, a value added tax increase also appreciates the real exchange rates based on unit labor costs.     

A sequential approach to testing for structural change in econometric models

The paper shows that the sequential approach to testing econometric models, particularly testing for structural change, is both feasible and potentially very useful. In fact, this paper makes clear the possibility of using the sequential approach as suggested by Dhrymes et al. (1972) and shows that the statistical dependence between successive tests can be overcome in some cases.Helpful comments by David Hendry, Grayham Mizon and Jan Kiviet, on an earlier version of a related Paper, are gratefully acknowledged.     

The econometric critique of computable general equilibrium modeling: the role of functional forms

Computable general equilibrium (CGE) models are among the most influential tools in applied economics. However, some serious questions have been raised about the empirical validity of these models. The core of the critique is that the parameter selection criteria are unsound and the use of first-order (CES class) functional forms imposes influential restrictions on the model's structure. A formal summary of the case against standard CGE modeling is presented, as is an alternative econometric-based modeling strategy which answers the critique. We then present a comparative CGE modeling experiment designed to assess the role of function forms. It is found that choice of functional forms affects not only industry-specific results, but aggregate results as well, even for small policy shocks.     

The demand for paper and paperboard: econometric models for the European Union

Cost minimization theory suggests national demand equations for paper and paperboard in which demand is a negative function of the price of paper and paperboard, and a positive function of gross national product. A dynamic version of this model was estimated with data from European Union countries, for newsprint, printing and writing paper, and other paper and paperboard. Country-by-country equations proved unstable. Pooling the data across countries, with dummy variables to account for fixed country effects, led to well defined short-term and long-term elasticities with respect to price and gross national product. The hypothesis that income and price elasticities were the same across the European Union countries could not be rejected at the 1% significance level, for the three product groups. From 1969 to 1995, most of the growth in demand had been due to the growth in national product, while price increases had only a small negative effect.     

Steady state distributions for models of locally explosive regimes: Existence and econometric implications

The purpose of this paper is to examine the properties of locally explosive regimes in the light of steady state results for threshold auto-regressive (TAR) models recently derived by Knight and Satchell (2011) [Journal of Time Series Econometrics, 3]. We study the conditions under which a steady state distribution of deviations of asset prices from fair value can be obtained using our simple model based on our particular definition of a bubble, noting that it is applicable to locally explosive regimes. After deriving general results, the analysis is further extended by considering the steady state distribution in three cases of a normally distributed error process, a non normally (exponentially) distributed steady-state process and a switching random walk with a fairly general iid error process. Then, the issues related to unit root testing for the presence of bubbles using standard econometric procedures are examined. Our results shed light on the ubiquitous finding of no bubbles in the econometric literature.     

The econometric challenge to system dynamics and vice versa: Some future perspectives

In the last years, there have been some attempts to compare different approaches for dynamic modeling of socioeconomic systems and to suggest guidelines for choosing among them. This paper continues these efforts with special emphasis on system dynamics and econometrics, which are commonly regarded as the roughest competitors in this field of simulation. It will present a detailed catalogue of model features, relevant for an adequate characterization of system dynamics and econometrics, and will stress the importance to notice the interconnections that exist between different features. The paper then gives a systematic survey of the conceivable relations between system dynamics and econometrics, and closes with a short epistemological outlook.