The String Tension in Gauge Theories: a Suggestion for a New Measurement Method

We discuss a new method for testing confinement and measuring the string tension (in the Coulomb gauge). Our numerical simulations demonstrate that the problems related to Gribov copies are not harmful and that the method is effective in the case of pure gauge Q.C.D.. We discuss the relevance of the method for studying gauge theories coupled to fermionic matter.Comment: 9 pages, Latex style, 4 postscript figures appended, ROMA 92-90

Experience, Innovation and Productivity - Empirical Evidence from Italy's Slowdown

We investigate the role of workers’ and managerial experience as a determinant of firm innovation and productivity in a sample of Italian manufacturing firms. A high share of temporary – thus un-experienced - workers is associated to low innovation and productivity. The effect of managerial experience measured by age on firm performance depends instead on the type of firm: high age of managers and board members is bad for innovation and productivity growth, while costs and benefits of old managerial age cancel out for non-innovative firms.firm productivity, innovation, managerial experience, temporary jobs

The Overlap between Headache and Epilepsy in the Light of Recent Advances in Medical Genetics

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One-loop topological expansion for spin glasses in the large connectivity limit

We apply for the first time a new one-loop topological expansion around the Bethe solution to the spin-glass model with field in the high connectivity limit, following the methodological scheme proposed in a recent work. The results are completely equivalent to the well known ones, found by standard field theoretical expansion around the fully connected model (Bray and Roberts 1980, and following works). However this method has the advantage that the starting point is the original Hamiltonian of the model, with no need to define an associated field theory, nor to know the initial values of the couplings, and the computations have a clear and simple physical meaning. Moreover this new method can also be applied in the case of zero temperature, when the Bethe model has a transition in field, contrary to the fully connected model that is always in the spin glass phase. Sharing with finite dimensional model the finite connectivity properties, the Bethe lattice is clearly a better starting point for an expansion with respect to the fully connected model. The present work is a first step towards the generalization of this new expansion to more difficult and interesting cases as the zero-temperature limit, where the expansion could lead to different results with respect to the standard one.Comment: 8 pages, 1 figur

Ensemble renormalization group for disordered systems

We propose and study a renormalization group transformation that can be used also for models with strong quenched disorder, like spin glasses. The method is based on a mapping between disorder distributions, chosen such as to keep some physical properties (e.g., the ratio of correlations averaged over the ensemble) invariant under the transformation. We validate this ensemble renormalization group by applying it to the hierarchical model (both the diluted ferromagnetic version and the spin glass version), finding results in agreement with Monte Carlo simulations.Comment: 7 pages, 10 figure

Labor Taxes and Wages: Evidence from Italy

We study the empirical relationship between labor taxation and pretax wages in Italy. We find that higher tax progressivity increases pretax wages. To explain this result, we introduce in an informal way a relative wage effect and argue that the combination of this effect with the labor supply effect dominates the wage moderation effect. We find also evidence that changes in payroll taxes are not fully absorbed by offsetting changes in the pretax wage and affect labor costs and employment. The evidence on the effect of the average income tax rate on pretax wages is more mixed, but it also points to the presence of some degree of real wage resistance. Finally, we find significant differences in the relationship between labor taxes and pretax wages by age group but not by skill or region of residence.progressive taxation, wage determination, Italy

Labor market rigidity, social policies and the labor share: Empirical evidence before and after the big crisis

This paper provides evidence of the impact of three important and general policies shaping the degree of labor market rigidity on the labor share: welfare expenditures, government expenditures on active labor market programs, and passive labor market measures. It analyzes the impact of regulation, such as the intensity of employment protection, and evaluates whether trade unions and minimum wage institutions play a role in the relationship between all measures and the labor share. The labor income share has experienced a declining trend since the mid-1970s in most advanced economies, and the existing literature found little if no correlation of this decline to general labor market characteristics. However, the present paper finds that some institutions are correlated to the downward trend, depending on the welfare system adopted, and that welfare and employment protection counteract the decline. Moreover, many countries saw an upsurge in their labor share after the burst of the financial crisis. Evidence of whether the effect of the policies weakened or reinforced the labor share after 2007 is reported

Taking equality seriously

In this thesis, I attempt to reconcile two alternative approaches to justice: distributive and relational egalitarianism. When examining the two accounts, I claim that relational egalitarianism has distributive egalitarian implications. This implies an extensional overlap between the two accounts, namely a correspondence between the normative outcomes of relational and distributive egalitarianism. This work is addressed primarily to relational egalitarian scholars, as well as others who are convinced by the value of relational equality as a worthy moral and political ideal. My aim is to prove that their goal implies embracing equality of distribution beyond relational equality. When making the case that relational egalitarians should take equality seriously, I claim that they should refrain from embracing distributive principles other than – or incompatible with – principles of distributive equality. This statement entails both a negative and a positive thesis. On the negative side, we should be critical toward the prominent tendency within the relational egalitarian debate, as influenced by the work of Elizabeth Anderson (1999), to reject claims of distributive egalitarian justice in favour of sufficientarian claims of distribution. On the positive side, distributive equality is required by the logic of relational egalitarianism, although its normative significance exists independently of it. While presenting my statements, I provide support for the externalist understanding of relational equality as most recently advanced by Kasper Lippert-Rasmussen (2018), through which the egalitarian character of someone’s relation depends on features external to their relation, such as on the distribution of the relevant currency among them. Whether or not individuals relate to one another as equals – I maintain – depends not merely on the internal feature of their relation, that is, on how they perceive or regard one another, but also, significantly, on how goods such as resources, welfare or opportunities are distributed among them. On my account, individuals are only equals when they recognize each other as equal in status and grant one another an equal share of the justice-relevant good. In defending my thesis, I critically engage with the literature on both distributive egalitarianism and relational egalitarianism. In particular, in the first part, I reconstruct the egalitarian debate and its approach to equality as either a relational or a distributive ideal. In the second part, I question such either/or relation by arguing that relational equality implies distributive equality, because arbitrary distributive inequality violates the deliberative constraint of relating as equals. I strengthen this claim by looking at the particular instantiation of distributive inequality in the field of education, and unveil its theoretical implications while supporting the project of reconciling distributive egalitarian and relational egalitarian approaches to justice. In my view, relational and distributive egalitarianism are compatible theories within one and the same egalitarian framework. Their normative outcomes are – at least in part – equivalent