Quasi‐Symmetric Graphical Log‐Linear Models

Abstract. We propose an extension of graphical log‐linear models to allow for symmetry constraints on some interaction parameters that represent homologous factors. The conditional independence structure of such quasi‐symmetric (QS) graphical models is described by an undirected graph with coloured edges, in which a particular colour corresponds to a set of equality constraints on a set of parameters. Unlike standard QS models, the proposed models apply with contingency tables for which only some variables or sets of the variables have the same categories. We study the graphical properties of such models, including conditions for decomposition of model parameters and of maximum likelihood estimates.     

ALIENATION AND INDUSTRIAL SOCIETY: A STUDY OF WORKERS‘ SELF-MANAGEMENT*

L'auteur examine un certain nombre d'hypothèses-clés émises par les socialistes sur les sociétés capitalistes et socialistes. (1) Est-ce que l'usine autogérée est plus pluraliste ou plus démocratique que la firme capitaliste? (2) Est-ce que l'ouvrier d'une usine autogérée croit que sa condition s'est améliorée? (3) Est-ce que l'usine autogérée est associée à des niveaux d'aliénation plus bas? (4) Est-ce que l'appartenance à une class sociale est reliée aux niveaux d'aliénation? (5) Est-ce que la participation à l'autogestion est associée à des niveaux d'aliénation plus bas? (6) Est-ce que l'aliénation dans l'usine est fortement associée a l'aliénation dans la société? Sur les six hypothèses émises, trois sont confirmées (1,2,5), les résultats de deux autres sont mêlées mais penchent vers la confirmation (3,6), et une seule hypothèse est infirmée (4). Par conséquent, on peut dire en conclusion générale que les suppositions principales sur la forme du socialisme d'autogestion semblent bien fondées. A number of key hypotheses proposed by socialists about capitalist and socialist societies are tested. (1) Is the workers' self-managed factory more pluralist or democratic than the capitalist firm? (2) Does the employee of a workers' self-managed factory perceive his condition as having improved? (3) Is the workers' self-managed factory associated with lower alienation levels? (4) Does class membership relate to alienation levels? (5) Is participation in self-management associated with lower alienation levels? (6) Is alienation in the factory strongly related to alienation in society? Of the six hypotheses posed, three were confirmed (1,2,5), two findings were mixed but leaned in the direction of confirmation (3,6), and only one hypothesis was disconfirmed (4). Thus, the general findings are that the central assumptions of the workers' self-management form of socialism seem to be sound.     

THE EFFECT OF CONCEALED WEAPONS LAWS: AN EXTREME BOUND ANALYSIS

Lott and Mustard [1997] provide evidence that enactment of concealed handgun ("right-to-carry") laws deters violent crime and induces substitution into property crime. A critique by Black and Nagin [1998] questions the particular model specification used in the empirical analysis. In this paper, we estimate the "model uncertainty" surrounding the model specified by Lott and Mustard using an extreme bound analysis (Leamer [1983]). We find that the deterrence results are robust enough to make them difficult to dismiss as unfounded, particularly those findings about the change in violent crime trends. The substitution effects are not robust with respect to different model specifications. (JEL K42)     

'More Myth than Reality': the Independent Artisan in Nineteenth Century Sheffield

Abstract In the context of an industrial revolution dominated by technological change and factory-based production, nineteenth century Sheffield has been perceived as differing from the norm. Small workshops, numerous outworkers and the retention of handicraft skills have charcterised the cutlery trades until the present century and these economic structures are said to have produced a backward looking but independent and robust artisan class. In this paper we argue that the robust artisan was more a creature of myth than reality. We point to the critical role of the factor in the nineteenth century cutlery trade for an understanding of the slide of the little master into dependence.     

Measures of Mortality Risks

Different risks of death are not equivalent because of differences in timing. This paper develops measures of mortality risks that recognize the probability of death, the duration of life lost, and the role of discounting. These adjustments lead to a substantial reordering of the major causes of death. Recognition of duration-related issues explains much of the public's misperception of mortality risk probabilities, which may reflect duration-related concerns rather than biases in risk beliefs. Our estimates suggest that in forming their risk beliefs the public discounts years of life lost at a rate from 3.3–12.4 percent. Standardization of lifetimes at risk also alters the relative efficacy of regulatory policies for which we provide a variety of cost-effectiveness measures.     

ESTIMATING TIME‐VARYING BARGAINING POWER: A FISHERY APPLICATION

We propose an unobserved‐components‐inspired approach to estimate time‐varying bargaining power in bilateral bargaining frameworks. We apply the technique to an ex‐vessel fish market that changed management systems from a regulated open‐access system to an individual fishing quota (IFQ) system over the timespan analyzed. We find that post‐IFQ implementation fishers do improve their bargaining power and thus accrue more of the rents generated by the fishery. However, unlike previous studies, we find that fishers do not move to a point of complete rent extraction. Rather, fishers and processors appear to be in a near‐symmetric bargaining situation post‐IFQ implementation. (JEL C22, L11, Q22)     

ACADEMIC PUBLICATION, MARKET SIGNALING, AND SCIENTIFIC RESEARCH DECISIONS

Publication is an essential scientific activity, but dangers arise when it is the primary signal of professional ability. This paper presents a simple model of screening in academic job markets. Signaling pressures may bias research decisions toward orthodox, low-risk projects, denying science the bold hypotheses and vigorous competition necessary for significant advance. Screening mechanisms help explain patterns of development noted by some historians of science as well as differences in these patterns across disciplines. The paper concludes with some comments on signaling and scientific change in economics.