Impostazione Bayesiana di un problema di analisi discriminatoria nell'ambito di un modello non parametrico

Seguendo l'impostazione predittiva delineata da J. Aitchison e I. R. Dunsmore (1975) viene proposto un modello non-parametrico di analisi discriminatoria dal punto di vista bayesiano.Si ricorre a tal fine ad una versione modificata dello schema di scambiabilità parziale e si utilizza il processo «mistura di prodotti di processi di Dirichlet» introdotto da D. M. Cifarelli ed. E. Regazzini (1978). Si presenta infine un'applicazione del modello ad un tipico problema di diagnosi medica.

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J. Aitchison and I. R. Dunsmore (1975) have stressed the importance of the predictive distribution for the solution of classical statistical problems. Following this approach we show initially how a modified version of the model of partial exchangeability can be usefully applied to derive the so called diagnostic distribution. Subsequently a nonparametric model of discriminatory analysis is derived, wherein a crucial role is played by a particular process named «mixture of products of Dirichlet processes» introduced by D. M. Cifarelli and E. Regazzini (1978) following a paper by C. E. Antoniak (1974) which in turn generalized the well known Dirichlet process developed by T. S. Ferguson (1973). Finally a numerical application to a medical problem is provided.

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Versione definitiva pervenuta il 24-9-81

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Lavoro eseguito nell'ambito del GNAFA-CNR. L'argomento di questo lavoro mi è stato suggerito dal professor Eugenio Regazzini. A quest'ultimo ed al prof. Donato Michele Cifarelli sono grato per avermi segnalato alcune oscurità nel testo originario.     

The Adjustment Property

An input–output (IO) system which is capable of producing any semi-positive net product by an adequate choice of the activity levels of its processes satisfies the ‘adjustment’ property. We analyze under which conditions the adjustment property holds for IO systems in which some produced goods have a purely intermediate character. The peculiarity of these pure capital goods is that final demand for them is identically zero. One of the ways to deal with this type of system is to eliminate the pure capital goods, by means of vertical integration.     

The role of ethics and product personality in the intention to purchase organic food products: a structural equation modeling approach

The aim of the present study is to examine the role of ethical dimensions and product personality in the purchasing intention of organic food products. The Prospect method (Caprara et al. in Test Psicomet Metodol 7(3–4):113–128, 2000), which integrates the Five factors model of personality (cf. Digman in Annu Rev Psychol 41(1):417–440, 1990) and the Theory of planned behavior (Ajzen in Organ Behav Hum Decis Process, 50(2):179–211, 1991) extended to an ethical dimension, was employed, by using a Structural Equation Modeling approach. Results showed that moral norms—i.e., personal beliefs regarding what is right or wrong (Parker et al. in Br J Soc Psychol, 34(2):127–137, 1995)—can be considered the main motivator of purchasing intention, and they are, in turn, affected by subjective norms and product personality traits of Naturalness and Authenticity. Marketing implications for firms operating in the organic food industry are discussed, in their intent to shift from a “niche” market to a broader diffusion of these products.     

Neither bad apple nor bad barrel: how the societal context impacts unethical behavior in organizations

Every time another corporate scandal captures media headlines, the ‘bad apple vs. bad barrel’ discussion starts anew. Yet this debate overlooks the influence of the broader societal context on organizational behavior. In this article, we argue that misbehaviors of organizations (the ‘barrels’) and their members (the ‘apples’) cannot be addressed properly without a clear understanding of their broader context (the ‘larder’). Whereas previously, a strong societal framework dampened the practical application of the Homo economicus concept (business actors as perfectly rational and egocentric utility‐maximizing agents without any moral concern), specialization, individualization and globalization led to a business world disembedded from broader societal norms. This emancipated business world promotes a literal interpretation of Homo economicus among business organizations and their members. Consequently, we argue that the first step toward ‘healthier’ apples and barrels is to sanitize the larder, that is, adapt the framework in which organizations and their members evolve.     

Dynamic inefficiency in an overlapping generations economy with production

Reichlin [Equilibrium cycles in an overlapping generations economy with production, J. Econ. Theory 40 (1986) 89-102] has shown in an OLG model with productive capital that whenever the steady state is locally indeterminate and undergoes a Hopf bifurcation, it is Pareto-optimal. While these results were established under the assumption of Leontief technology, the author has partially extended them to show that the Hopf bifurcation is robust with respect to the introduction of capital-labor substitution. In this note, we prove that the Pareto-optimality of the steady state does not extend to technologies with capital-labor substitution. When the steady state is a sink or undergoes a Hopf bifurcation, it is characterized by over-accumulation with respect to the Golden Rule—the interest rate is negative—hence not Pareto-optimal. Most importantly, it follows that stabilization policies targeting the steady state leave room for welfare losses associated with productive inefficiency, apart from the very special case of Leontief technology.     

Agro-Manufactured Export Prices, Wages and Unemployment

This article estimates the impacts of world agricultural trade liberalization on wages and unemployment in Argentina in the presence of individual labor supply responses and adjustment costs in labor demand. After a 10% increase in agro-manufactured export prices, I find that: ( a ) the employment probability would increase by 1.36 percentage points, matched by a decline in the unemployment probability of 0.75 percentage points and an increase in labor market participation of 0.61 percentage points; ( b ) the unemployment rate would decline by 1.23 percentage points; ( c ) expected wages would increase by 10.3%, mostly due to higher employment probabilities.     

Deindustrialisierung: Eine neue „britische Krankheit“?

In vielen EU-L?ndern ist ein Rückgang der Besch?ftigung im gewerblichen Bereich zu beobachten. Besonders ausgepr?gt ist die „Deindustrialisierung“ jedoch in Gro?britannien—bei gleichzeitiger Ausweitung des Dienstleistungsbereichs. Welches sind die Ursachen dieser Entwicklung? Ist dieser Prozess als neue „britische Krankheit“ zu bezeichnen oder Ausdruck einer relativ dynamischen und flexiblen Wirtschaft? Ist in Deutschland eine ?hnliche Entwicklung zu erwarten? Die Autoren vertreten hier ihre pers?nliche Meinung und nicht notwendigerweise die der Deutschen Bundesbank.