Revealed preferences: A topological approach

The purpose of this paper is to study the relationship between the axiomatic foundations of revealed preference theory and the continuity properties of choice. The main result of this paper shows that the continuity of a set-to-point choice function is equivalent to the weak axiom of revealed preference and openness of the strict revealed relation, provided that the collection of budget sets is endowed with a topology used widely by economists.     

A theory of time preferences over risky outcomes

This paper provides two representation theorems for time preferences. They both cover as special cases a variety of time preference models considered in the experimental and theoretical literatures on intertemporal choice. In particular, similarity relations on time and outcomes, exponential, quasi-hyperbolic and hyperbolic discounting are special cases of the theorems. This approach identifies certain factors that are common to time preference structures which look so different.The paper builds on the recent work by Masatlioglu and Ok [Masatlioglu, Y., Ok, E., 2008. A theory of (relative) discounting. Journal of Economic Theory, in press] on Euclidean bundles and obtains similar representation theorems for the case of compact, separable and connected spaces of bundles. My work allows for the inclusion of the case in which bundles are lotteries.     

Technical efficiency of Norwegian banks: The non-parametric approach to efficiency measurement

The nonparametric frontier methodology is applied to a sample of banks, where output levels are measured either by the number of accounts and their average size, or by the total balances of the accounts. The efficiency rankings of individual banks are found to depend substantially on our choice of output metric, whereas the estimated size of potential productivity improvements in the banking sector are less affected. The results on economies of scale are also largely unchanged.The refereeing process of this paper was handled through S. Grosskopf.     

Productivity changes in Swedish pharamacies 1980–1989: A non-parametric Malmquist approach

In this article we develop a non-parametric (linear programming) approach for calculation of a Malmquist (input based) productivity index. The method is applied to the case of Swedish pharmacies.The authors thank three anonymous referees for their important comments.     

A bootstrap-based non-parametric forecast density

Interest in density forecasts (as opposed to solely modeling the conditional mean) arises from the possibility of dynamics in higher moments of a time series, as well as in forecasting the probability of future events in some applications. By combining the idea of Markov bootstrapping with that of kernel density estimation, this paper presents a simple non-parametric method for estimating out-of-sample multi-step density forecasts. The paper also considers a host of evaluation tests for examining the dynamic misspecification of estimated density forecasts by targeting autocorrelation, heteroskedasticity and neglected non-linearity. These tests are useful, as a rejection of the tests gives insight into ways to improve a particular forecasting model. In an extensive Monte Carlo analysis involving a range of commonly used linear and non-linear time series processes, the non-parametric method is shown to work reasonably well across the simulated models for a suitable choice of the bandwidth (smoothing parameter). Furthermore, an application of the method to the U.S. Industrial Production series provides multi-step density forecasts that show no sign of dynamic misspecification.     

Efficiency measurement when producers control pollutants: a non-parametric approach

This paper treats efficiency measurement when some outputs are undesirable and producers control pollutants by end-of-pipe or change-in-process abatement. A data envelopment analysis framework that compares producers with similar pollution control efforts is proposed. First, my approach avoids arbitrary disposability assumptions for undesirable outputs. Second, the model is used to evaluate the interplay between pollution control activities and technical efficiency. I compare my approach to the traditional neo-classical production model that does not incorporate undesirable outputs among outputs, and to Färe et al.’s (Rev Econ Stat 71:90–98, 1989, J Econom 126:469–492, 2005) well-known model that incorporates bads. I evaluate the common assumption in the literature on polluting technologies, that inputs are allocatable to pollution control, and apply U.S. electricity data to illustrate my main point: Although my empirical model specifications are in line with the literature on polluting technologies, they rely on inputs that play an insignificant role in controlling nitrogen oxides (NO_x) emissions. Consequentially, there are no reasons to expect the efficiency scores of the traditional model to differ from the efficiency scores of the other two models that account for resources employed to pollution control. Statistical tests show that my model, which explicitly takes pollution control efforts into account, produces efficiency scores that are not statistically different from the traditional model’s scores for all model specifications, while Färe et al.’s model produces significantly different results for some model specifications. I conclude that the popular production models that incorporate undesirable outputs may not be applicable to all cases involving polluting production and that more emphasis on appropriate empirical specifications is needed.     

A non-parametric test for industrial specialization

We introduce a non-parametric microdata based test for industrial specialization and apply it to a single urban area. Our test employs establishment densities for specific industries, a population counterfactual, and a new correction for multiple hypothesis testing to determine the statistical significance of specialization across both places and industries. Results highlight patterns of specialization that are extremely varied, with downtown places specializing in a number of service sector industries, while suburban places specialize in both manufacturing and service industries. Business service industries are subject to more specialization than non-business service industries while the manufacturing sector contains the lowest representation of industries with specialized places. Finally, we compare results for specialization with localization and show that both measures contribute to our understanding of industry and place specific agglomerative forces.     

A non-parametric independence test using permutation entropy

In the present paper we construct a new, simple, consistent and powerful test for independence by using symbolic dynamics and permutation entropy as a measure of serial dependence. We also give a standard asymptotic distribution of an affine transformation of the permutation entropy under the null hypothesis of independence. The test statistic and its standard limit distribution are invariant to any monotonic transformation. The test applies to time series with discrete or continuous distributions. Eventhough the test is based on entropy measures, it avoids smoothed non-parametric estimation. An application to several daily financial time series illustrates our approach.     

A Bayesian non-parametric estimate for multivariate regression

The predictive approach to inference in multivariate regression problems is considered in a Bayesian non-parametric framework. A simple estimate of the regression coefficient matrix is derived under the Dirichlet process prior and then generalized by using a mixture of Dirichlet processes prior. These estimates are shown to belong to the class of linear Bayes estimates and their relation to ridge regression estimates is also exhibited. The paper ends with an illustrative application.     

Forecasting intermittent demand by hyperbolic-exponential smoothing

Croston’s method is generally viewed as being superior to exponential smoothing when the demand is intermittent, but it has the drawbacks of bias and an inability to deal with obsolescence, where the demand for an item ceases altogether. Several variants have been reported, some of which are unbiased on certain types of demand, but only one recent variant addresses the problem of obsolescence. We describe a new hybrid of Croston’s method and Bayesian inference called Hyperbolic-Exponential Smoothing, which is unbiased on non-intermittent and stochastic intermittent demand, decays hyperbolically when obsolescence occurs, and performs well in experiments.     

对研发费用会计处理的思考

<正> 我国新的《企业会计制度》规定:在研究和开发过程中发生的研发费用直接计入当期损益,不得资本化;在目前的会计实务中,研发费用一般也是作为期间费用处理的,属于管理费用中的一项;但在理论界,对研发费用是否资本化还存在诸多争议。笔者认为,企业的研究与开发活动,目的是让企业在未来能更好地发展,与未来各期的收益密切相关,所以研发费用在本质上是一项资本性支出,应确认为企业的无形资产,并按一定方法在收益期内进行摊销。     

A non-parametric test for independence based on symbolic dynamics

In the present paper we propose a powerful, yet simple, non-parametric test for independence based on symbolic dynamic analysis. The absence of dependences in the unknown underlying data generating process is studied via symbolic dynamics. This is possible due to the ordering property of real numbers on an interval. Interestingly, the test is closely related to entropy concepts. Apart from being correctly sized, the new test is powerful for realistic finite data sets, and it is easy to use as one does not need to select any free parameter, which sharply contrasts with other tests of independence. In addition, the test is robust in the presence of noise which is one of the most typical cases when dealing with economic time series.     

Smoothing demand by aggregation with respect to wealth

We suggest in this paper to treat the problem of smoothing demand by aggregation in a two-step procedure, corresponding to the two different constituents of consumption characteristics, wealth and preferences. Instead of imposing a manifold structure on preferences we exploit the nice structure of wealth-space. The first step of this procedure, aggregation with respect to wealth, is carried out. It is shown that, for any preference, aggregation with respect to wealth yields a mean demand which is almost everywhere C¹. Moreover, it is shown that for an important class of preferences, vanishing Gaussian curvature of indifference surfaces does not destroy differentiability of the mean demand function.     

On preferences over subsets and the lattice structure of stable matchings

This paper studies the structure of stable multipartner matchings in two-sided markets where choice functions are quotafilling in the sense that they satisfy the substitutability axiom and, in addition, fill a quota whenever possible. It is shown that (i) the set of stable matchings is a lattice under the common revealed preference orderings of all agents on the same side, (ii) the supremum (infimum) operation of the lattice for each side consists componentwise of the join (meet) operation in the revealed preference ordering of the agents on that side, and (iii) the lattice has the polarity, distributivity, complementariness and full-quota properties. Received: 5 March 1999 / Accepted: 12 May 2000     

An index aggregation approach to comparing the overall performance of emerging and developed countries

An index aggregation approach is proposed to carry out comparisons of BRICSAM, a populous rapidly growing economic group consisting of Brazil, Russia, India, China, South Africa, Association of South-East Asian Nations (ASEAN), and Mexico with Group of Seven (G7), the most developed country club including Canada, France, Italy, Japan, Germany, United Kingdom and the United States. It is estimated that by 2050 the accelerated economic activity of BRICSAM could have significant impact on investment flows, legal and regulatory frameworks, the stability of political institutions, human capital and migration flows, competition policy, intellectual property rights, and social and environmental policies. The comparison analyses of BRICSAM and G7 countries could assist people to better understand the status quo of these countries in the global economy and international system, particularly in the areas of economics and responsible activities such as sustainable development, global commitments and transparent practices. Many country-ranking indices, such as the indices given in the global competitiveness report by the World Economic Forum, and the environmental sustainability index by Yale University, constitute evaluations of countries from different perspectives. This paper proposes a data envelopment analysis-based approach to aggregate different ranking indices for BRICSAM and the G7 countries. The approach can provide a fair overall assessment of a country's standing by maximizing its possibility of obtaining the best possible result.     

A non-parametric statistical model for the control of Italian insurance companies

The problem of evaluating the solvency of insurance companies is tackled through the use of a non-parametric statistical model, constructed using decision-tree techniques. The model is tested on a sample of Italian non-life insurance companies and its performance over the test period compared with those of linear and quadratic parametric models.

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Riassunto Il problema della valutazione della solvibilità delle imprese di assicurazione è affrontato con l'impiego di un modello statistico non parametrico, costruito con le tecniche degli alberi delle decisioni. Viene proposta una sperimentazione del modello su un campione di imprese assicuratrici italiane operanti nei rami nonvita ed effettuata una analisi comparata intertemporale con gli standards di efficienza registrati su modelli parametrici lineare e quadratico.

     

Comment on: A non-parametric spatial independence test using symbolic entropy

In a recent paper López et al. (2010) introduce a new test for spatial independence. The test is a generalization of tests developed in Matilla-García (2007) and Matilla-García and Marín (2008). The results derived need some clarification.