A family of inverse demand systems and choice of functional form

Barten's (1992) analysis of choice of functional form for quantity-dependent demand systems is extended to price-dependent or inverse demand systems. Alternative inverse demand systems combining the features of the Rotterdam inverse demand and almost ideal inverse demand systems are examined. Choice of functional form is made through a synthetic model which under appropriate restrictions yields the different inverse demand systems. The synthetic model itself can also be considered a more flexible specification.     

Learnability and rationality of choice

In this paper we study the learnability of the class of rationalizable choice functions using the basic concept of PAC-learnability from statistical learning theory. We prove that the class of rationalizable choice functions on N alternatives is learnable from O(N) examples and is optimal in terms of PAC-learnability among classes which are invariant under permutations of the elements.     

Excess demand functions when new assets are introduced

We demonstrate that information on the aggregate excess demand function of an incomplete real asset market economy is not helpful toward predicting the equilibrium of a new economy to which unredundant assets are added. An innovation of assets can completely change the aggregate excess demand functions.     

Excess demand functions with incomplete markets—a global result

The purpose of this paper is to give a global characterization of excess demand functions in a two-period exchange economy with incomplete real asset markets. We show that continuity, homogeneity and Walras’ law characterize the aggregate excess demand functions on any compact price set which maintains the dimension of the budget set.     

Empirical determination of aggregate demand and supply curves: The example of the RWI Business Cycle Model

Macroeconometric models are often criticised for being too complex and difficult to read in theoretical terms. To overcome these difficulties, Hickman suggested the calculation of a model's implicit aggregate demand/supply (AD/AS) structure. The method helps to understand models and their main properties in theoretical terms and facilitates detailed model comparisons. This paper uses the AD/AS–IS/LM apparatus to analyse the simulation properties of the RWI (Rheinisch-Westfälisches Institut für Wirtschaftsforschung) Business Cycle Model, a medium-sized short-term macroeconometric model for Germany. The results confirm theoretical expectations for AD and AS elasticities and reveal particular reactions linked to peculiar model specifications such as an endogenous government sector. The results are also much in line with a previous study in a multi-country model context.     

Effective global regularity and empirical modelling of direct, inverse, and mixed demand systems

Abstract .  This paper utilizes the notion of 'effective global regularity' and the intuition stemming from Cooper and McLaren (1996)'s General Exponential Form to develop a family of 'composite' (product and ratio) direct, inverse and mixed demand systems. Apart from having larger regularity regions, the resulting specifications are also of potentially arbitrary rank, which can better approximate non-linear Engel curves. We also make extensive use of duality theory and a numerical inversion estimation method to rectify the endogeneity problem encountered in the estimation of the mixed demand systems. We illustrate the techniques by estimating different types of demand systems for Japanese quarterly meat and fish consumption.     

Exploring the effects of aggregation error in the estimation of consumer demand elasticities

Errors introduced by using aggregate data in estimating a consumer demand model have long been a concern. We study the effects of such errors on elasticity estimates derived from AIDS and QUAIDS models. Based on a survey of published articles, a generic parameterization of the income distribution, and the range of Gini coefficients reported for 28 OECD countries, we generate and analyze a large number of “observations” on the differences between elasticities calculated at the aggregate level and those calculated at the micro level. We suggest a procedure for evaluating the likely range of aggregation error when a model is estimated with aggregate data.     

Testing for structural break in Japanese demand system after the bubble era

The aims of this paper are two: to define the structural break in the Japanese demand system after the bubble era and to apply the structural break test developed by Andrews et al. (1996) within the framework of the cointegrated demand system. Our test results reject the null hypothesis of no structural break for March 1994 and then demonstrate the structural break after the bubble era. We define the concept of structural break as the time-series change in preference having the following two aspects: the change in preference for commodity prices by the decline in personal income and the change in preference regarding goods in the course of aging effect, with the improvement of living standards.     

Stock exchange mergers and weak form of market efficiency: The case of Euronext Lisbon

This exploratory paper is among the first to examine the impact of stock exchange mergers on informational market efficiency. We focus on the merger of Bolsa de Valores de Lisboa e Porto (Portuguese Stock Exchange) with Euronext in 2002 (that created Euronext Lisbon). To investigate this question we perform numerous statistical tests: serial correlation test (ACF test), runs test, unit root test (Kwiatkowski, Philips, Schmidt, & Shin, 1992), multiple variance ratio test (Chow & Denning, 1993) and ranks and signs test (Wright, 2000).The results indicate that the Portuguese Equity Market is inefficient in weak form during pre-merger period implying that investors possessed an opportunity to earn abnormal returns though small in magnitude. The results, sensitive to the methodology used, indicate a mixed evidence of improvement in market efficiency during the post-merger period. Although the findings are mixed, yet most tests show a tendency of improved efficiency.     

Carbon tax simulations using a household demand model

The main objective of this paper is to analyse consumer response and welfare effects due to changes in energy or environmental policy. To achieve this objective we formulate and estimate an econometric model for non-durable consumer demand in Sweden that utilises micro- and macro-data. In the simulations, we consider two revenue neutral scenarios that both imply a doubling of the CO₂ tax; one that returns the revenues in the form of a lower VAT and one that subsidise public transport. One conclusion from the simulations is that the CO₂ tax has regional distribution effects, in the sense that household living in sparsely populated areas carry a larger share of the tax burden.     

Empirical analysis of jump dynamics, heavy-tails and skewness on value-at-risk estimation

This study provides a comprehensive analysis of the possible influences of jump dynamics, heavy-tails, and skewness with regard to VaR estimates through the assessment of both accuracy and efficiency. To this end, the ARJI model, and its degenerative GARCH model with normal, GED, and skewed normal (SN) distributions were adopted to capture the properties of time-varying volatility, time-varying jump intensity, heavy-tails and skewness, for a range of stock indices across international stock markets during the period of the U.S. subprime mortgage crisis. Empirical results show that, with regard to the evaluation of accuracy, the role of jump dynamics is more substantial than heavy-tails or skewness as it pertains to VaR accuracy at the 90% and 95% levels, while heavy-tails become more important at the 99% level for a long position. However, the influence of the abovementioned properties on VaR estimation does not appear substantial for a short position. In addition, the properties of jump dynamics and skewness appear to be beneficial for the improvement of efficiency.     

Consumption choice and asset pricing with a non-price-taking agent

Summary. This paper develops a pure-exchange model to study the consumption-portfolio problem of an agent who acts as a non-price-taker, and to analyze the implications of his behavior on equilibrium security prices. The non-price-taker is modeled as a price leader in all markets; his price impact is then recast as a dependence of the Arrow-Debreu prices on his consumption, allowing a tractable formulation. Besides the aggregate consumption, the endowment of the non-price-taker appears as an additional factor in driving equilibrium allocations and prices. Comparisons of equilibria between a price-taking and a non-price-taking economy are carried out. Received: March 29, 1996; revised version October 29, 1996     

General equilibrium, wariness and efficient bubbles

Wary consumers overlook gains but not losses in remote sets of dates or states. As preferences are upper but not lower Mackey semi-continuous, Bewley?s (1972) [4] result on existence of equilibrium whose prices are not necessarily countably additive holds. Wariness is related to lack of myopia and to ambiguity aversion (and, therefore, to Bewley?s (1986) [6] work on Knightian uncertainty). Wary infinite lived agents have weaker transversality conditions allowing them to be creditors at infinity and for bubbles to occur in positive net supply assets completing the markets. There are efficient allocations that can only be implemented with asset bubbles.     

Fundamentals, information, and international capital flows: A welfare analysis

In the recent discussion surrounding the design of a new international financial architecture, enhancing transparency has widely been proposed as a policy essential for increasing the efficiency of international capital markets. This paper uses a simple two-country (two-agent) general equilibrium model with incomplete markets and production to explore the welfare consequences of an increase in public information about country-specific fundamentals (increase in transparency). An improvement in the quality of information has two effects on the ex ante welfare of individual countries: A direct effect that increases the efficiency of global capital allocation and welfare, and an indirect general equilibrium effect that increases asset price volatility and may decrease welfare. When the degree of risk-aversion is low, at least one country will gain from an increase in information quality. If the degree of risk-aversion is high, then there are robust examples of economies for which an increase in information hurts all countries. The paper also discusses how certain institutional arrangements (international derivative markets, international agency) could ensure that all countries gain from better information by providing insurance against information-induced asset price risk.     

Benford's Law as an Indicator of Fraud in Economics

Abstract. Contrary to intuition, first digits of randomly selected data are not uniformly distributed but follow a logarithmically declining pattern, known as Benford's law. This law is increasingly used as a 'doping check' for detecting fraudulent data in business and administration. Benford's law also applies to regression coefficients and standard errors in empirical economics. This article reviews Benford's law and examines its potential as an indicator of fraud in economic research. Evidence from a sample of recently published articles shows that a surprisingly large proportion of first digits, but not of second digits, contradicts Benford's law.     

Multiplicity in general financial equilibrium with portfolio constraints

This paper explores the role of portfolio constraints in generating multiplicity of equilibrium. We present a simple financial market economy with two goods and two households, households who face constraints on their ability to take unbounded positions in risky stocks. Absent such constraints, equilibrium allocation is unique and is Pareto efficient. With one portfolio constraint in place, the efficient equilibrium is still possible; however, additional inefficient equilibria in which the constraint is binding may emerge. We show further that with portfolio constraints cum incomplete markets, there may be a continuum of equilibria; adding incomplete markets may lead to real indeterminacy.     

Ticket pricing and the impression of excess demand

If willingness to pay depends on characteristics of other attendees, a monopolist will use a lineup as a screening mechanism only if a consumer's characteristic is inversely related to her cost of lining up. No capacity constraint is necessary.     

Viscous demand

In many markets, demand adjusts slowly to changes in prices, i.e., demand is “viscous”. This viscosity gives each firm some monopoly power, since it can raise its price above that of its competitors without immediately losing all of its customers. The resulting equilibrium pricing behavior and market outcomes can differ significantly from what one would predict in the absence of demand viscosity. In particular, the model explains the importance of market share as an investment, as well as “kinked demand curves”. It also explains how apparently “competitive” pricing behavior can lead to outcomes that mimic those of collusion.     

TESTING THE SEQUENTIAL LOGIT MODEL AGAINST THE NESTED LOGIT MODEL*

In this paper, we show that the sequential logit (SL) model, in which a choice process is characterized as a sequence of independent multinomial logit models, is a limiting case of the nested logit (NL) model. For testing the SL model against the NL model, we propose Wald, likelihood ratio and Lagrange multiplier tests after suitably reparameterizing the NL model. It is found that when the NL model parameters are “weakly identified”, the Wald test severely underrejects the true model, whereas the sizes of the LR and LM tests are not significantly affected.