Fit performance of several programs used for non-linear least squares problems

Seven computerprograms for non-linear regression or curve fitting problems are compared. The comparison of the programs, running in different computing centra, is restricted to the fit performance. Six model functions are fitted according to the least squares criterion to data series, arising from practical work. The special least squares minimization programs turned out to be better suited for these problems than general optimizing programs.     

Government Consumption and Industrial Productivity: Scale and Compositional Effects

Within a production function framework in which government spending produces public goods which enter firms production functions, empirical tests using time series data spanning eleven countries and thirty industries find both the scale and the composition of government consumption spending to affect the level and the rate of growth of total factor productivity at the industry level.Jel Classification: H50, D24     

A Stochastic Frontier Production Function with Flexible Risk Properties

This paper considers a stochastic frontier production function which has additive, heteroscedastic error structure. The model allows for negative or positive marginal production risks of inputs, as originally proposed by Just and Pope (1978). The technical efficiencies of individual firms in the sample are a function of the levels of the input variables in the stochastic frontier, in addition to the technical inefficiency effects. These are two features of the model which are not exhibited by the commonly used stochastic frontiers with multiplicative error structures.An empirical application is presented using cross-sectional data on Ethiopian peasant farmers. The null hypothesis of no technical inefficiencies of production among these farmers is accepted. Further, the flexible risk models do not fit the data on peasant farmers as well as the traditional stochastic frontier model with multiplicative error structure.     

The Case of the Missing Pollution Haven Hypothesis

One particularly vexing puzzle for economists and policymakers over the past several decades concerns the empirical significance of the theoretically predicted pollution haven hypothesis. While neoclassical theory and conventional wisdom both surmise that local economies will suffer deleterious effects from stricter environmental regulations, empirical studies have largely failed to validate such claims. This study utilizes the method of matching to show that the impact of stricter regulation is heterogeneous spatially, varying systematically based on location-specific attributes. Previous studies that assume a homogenous response may therefore inadvertently mask the overall impact of more stringent regulations by pooling unaffected and affected regions.JEL Classification: Q25, Q28, H00, L51, R1The authors wish to thank to Michael Crew, Anthony Heyes, an anonymous referee, Werner Antweiler, Randy Becker, Wayne Gray, Shelby Gerking, Michael Greenstone, Vern Henderson, and Arik Levinson. Participants at various university seminars and conferences also lent useful insights to this line of research.     

Volatility in the knowledge economy

Summary. We seek to explain the economic volatility of the last 6 years, in particular the rapid expansion and contraction of the knowledge sectors. Our hypothesis is that these sectors amplify the business cycle due to their increasing returns to scale, growing faster than others in an upswing and contracting faster in a downswing. To test this hypothesis we postulate a general equilibrium model with two sectors: one with increasing returns that are external to the firm and endogenously determined - the knowledge sector - and the other with constant returns to scale. We introduce a new measure of volatility of output, a real beta, and derive a resolving equation, from which we prove that the increasing return sectors exhibit more volatility then other sectors. We validate the main results on US macro economic data of real GDP by industry (2-3 digits SIC codes) of the 1977-2001 period, and provide policy conclusions.Received: 18 March 2002, Revised: 16 February 2004, JEL Classification Numbers: D5, D58, E10, L50, L52, O38, O51.Correspondence to: Graciela Chichilnisky     

An efficient budget allocation policy for decentralisation of responsibility for site decontamination projects

Selection and execution of site decontamination projects is often best left to local authorities, in accordance with the subsidiarity principle, even though the budget for such projects is made available through a central authority. In this paper we suggest a practical budget allocation policy which a central authority can employ to allocate budgets to local authorities, while still optimising the central authority's environmental objective function. The procedure is fully consistent with the principle of decentralisation of responsibility for selection and execution of projects, and requires a minimum information exchange between local and central levels. Despite the information asymmetry between local and central levels, incentive compatibility problems can be (partially) prevented by choosing an appropriate evaluation mechanism. At the same time, the procedure is computationally effective and efficient, and can guarantee a fair budget allocation, making it easy to implement and politically acceptable.     

OCCUPATIONAL EARNINGS BEHAVIOR AND THE INEQUALITY OF EARNINGS BY SEX AND RACE IN THE UNITED STATES*

This paper examines differences in earnings by occupations, and within occupations by sex and by race, on the basis of the 1/100 Public Use Samples of the 1960 and 1970 U.S. Population Censuses. It employs interval analysis to establish 32 categories of occupations with similar characteristics. Little relation was found between mean earnings of occupational groups and the degree of earnings inequality within them. When the figures are examined by sex, it was found that men, on average, earned over twice as much as women in both years, but women's earnings were more unequally distributed (as measured by the Gini coefficient). Women are concentrated in the traditional “female” occupations, which tend to be those at the bottom of the earnings scale, and men have a monopoly of the higher paid occupations. But mean earnings for men exceeded those for women in all occupational groups except one, even in the primarily female occupations. Standardizing first for occupational distribution and then for earnings by occupation, it was found that earnings differences between males and females within occupation had a greater impact on the overall male-female earnings ratio than did differences in occupational distribution by sex. In contrast, when the figures are examined by race, the change in occupational distribution (primarily the movement of blacks out of farming and of blacks and Spanish speakers out of personal services) was the major factor. There was also a considerable degree of earnings inequality within demographic groups. The degree of inequality was in the main reduced when the demographic groups were subdivided into occupations, but it was still substantial. Additional factors like time worked, schooling, and experience must be taken into consideration in understanding this phenomenon.     

The Economics and Bioeconomics of Folk and Scientific Classification

Synopsis This paper is the product of a collaboration between a biologist (Ghiselin 1997) who works on the philosophy of classification and an economist (Landa 1981, 1994) who works on the ‘Economics of Identity’: how and why people classify people based on identity in the context of a theory of ethnic trading networks. In developing the ‘bioeconomics’ (the synthesis of economics with biology) of classification, we crossed a number of disciplinary boundaries—anthropology, economics, sociology, biology, and cognitive psychology including evolutionary psychology’s ‘fast and frugal’ heuristics. Using a bioeconomics approach, we argue that folk classifications—the classifications used by ordinary persons—have much in common with scientific classifications: underlying both is the need for economy of information processing in the brain, for the efficient organization of knowledge, and for efficiency of information acquisition and transmission of information to others. Both evolve as a result of trial and error, but in science there is relatively more foresight, understanding, and planning.     

Una nuova caratterizzatione dell'ammissibilità nella teoria delle decisioni

In questo lavoro viene fornita una nuova caratterizzazione dell'ammissibilità attraverso un adeguato uso della nozione di ammissibilità parziale. Questa caratterizzazione consente di affrontare le questioni riguardanti la completezza della classe delle decisioni ammissibiliti sotto condizioni «maneggevoli». Fornisce inoltre un approccio unificante al problema della completezza che consente di derivare, come casi particolari, alcuni risultati già noti nella letteratura sull'argomento.

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In this paper a new characterization of admissibility is given for general decision problems. It is based on an adequate use of the notion of partial admissibility.A general decision problem is usually synthetized by a triplet (, , ) where is the states (or parameters) space, the set of available decisions and is a family of real valued functions defined on and expressing numerically the consequences of choosing when the state is . The set is regarded as a subset of the space of all real valued functions on endowed with the topology of pointwise convergence.As for as admissibility is concerned all the pertinent information about decisions are contained in the corresponding functionsW .This allows to introduce a notion of partial admissibility through the neigh-bourhoods of this topology. Admissibile decisions are then shown to be limits of monotone non increasing sequences of partially admissible decisions.Moreover this topological characterization allows to prove the completeness of classes of admissible decisions under acceptable systems of conditions which contain as special cases, known results in literature.

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Lavoro svolto nell'ambito del Gruppo Nazionale per l'Analisi Funzionale e le sue Applicazioni del C.N.R.