Conjugate Priors Represent Strong Pre-Experimental Assumptions

Abstract.  It is well known that Jeffreys' prior is asymptotically least favorable under the entropy risk, i.e. it asymptotically maximizes the mutual information between the sample and the parameter. However, in this paper we show that the prior that minimizes (subject to certain constraints) the mutual information between the sample and the parameter is natural conjugate when the model belongs to a natural exponential family. A conjugate prior can thus be regarded as maximally informative in the sense that it minimizes the weight of the observations on inferences about the parameter; in other words, the expected relative entropy between prior and posterior is minimized when a conjugate prior is used.     

Military conscription and university enrolment: evidence from Italy

This paper analyses the effect of the abolition of compulsory military service (CMS) on university enrolment in Italy. A triple-difference model is used to account for various potentially confounding factors. The identification strategy exploits variation along three dimensions: (a) between gender, (b) between age-groups and (c) between time periods. The results show that there is no statistically significant evidence suggesting that the abolition of CMS has a causal effect on the decision to enrol in university studies. Estimates obtained employing a double-difference model exploiting variation along the dimensions (a) and (b) overestimate the effect. Finally, although there is no statistically significant overall effect, we find some evidence of heterogeneous effects between students from different social backgrounds.     

Sensory analysis via multi-block multivariate additive PLS splines

In the last decade, much effort has been spent on modelling dependence between sensory variables and chemical–physical ones, especially when observed at different occasions/spaces/times or if collected from several groups (blocks) of variables. In this paper, we propose a nonlinear generalization of multi-block partial least squares with the inclusion of variable interactions. We show the performance of the method on a known data set.     

A Systematic Literature Review on Recent Lean Research: State‐of‐the‐art and Future Directions

Lean management (LM) has attracted the interest of scientists and practitioners since 1990, when Womack et al. (Womack, J.P., Jones, D.T. and Roos, D. (1990). The Machine that Changed the World. New York, NY: Rawson Associates) popularized the Japanese manufacturing approach aimed at eliminating waste to improve operational performance and customer satisfaction. Over the years, the lean concept has evolved becoming a managerial paradigm applicable to different sectors and processes with impressive results. This heterogeneity of implementations and settings makes the recent LM literature diverse and fragmented, and an extensive analysis of the latest contributions on this field is lacking. To address this gap, the authors propose a systematic literature review (SLR) of 240 articles published in 25 peer‐reviewed academic journals from January 2003 to December 2015. The purpose is to analyse the recent trends in this area and to provide a framework that organizes lean researched issues into mature, intermediate and nascent, based on their position in the research life cycle. Starting from the gaps that the SLR highlights, the authors suggest conducting lean research in the following directions: (a) grounding lean studies on existing managerial theories; (b) addressing service settings such as banking/finance, public sector and education; (c) exploring the role of national culture through cross‐country comparisons; (d) defining and conceptualizing ‘lean‐x’ processes; (e) understanding the relationships between lean and safety/environmental issues, and (f) unveiling the effects on social outcomes. Finally, the proposed framework helps scholars find issues not sufficiently explored that require theory‐building research (to move from nascent to intermediate) or theory‐testing research (to move from intermediate to mature).     

EQUILIBRIUM SEARCH UNEMPLOYMENT,ENDOGENOUS PARTICIPATION,AND LABOR MARKET FLOWS

The sustainability of welfare states requires high employment and high participation to raise the tax base. To analyze labor supply in a world with market frictions, we propose and solve a macro model of the labor market with unemployment and labor force participation as endogenous and distinct states. In our world, workers' decisions of participating are determined by an entry decision and an exit decision. A calibration of the model improves the usual representations of labor markets, since it quantitatively accounts for the observed flows between employment and nonparticipation. The paper investigates also the effect of payroll taxes and unemployment benefits on participation decisions. Taxes reduce entries and increase exits, whereas unemployment benefits, at a given job‐finding rate, raise entries and have ambiguous effects on exits. (JEL: J2, J6)     

Response surface methodology for non-equispaced experimental configurations applied to a discrete and stochastic simulator of a manufacturing company

This work is based on the construction and use of a SLAM II PC-based simulator for a medium-sized company manufacturing machine tools designed to work glass. Response surface methods and several experimental design techniques were applied to this company to optimize simulator performances. Since there is a feedback loop on the actual manufacturing system, the theory of orthogonal polynomials was applied to the case-study relative to a planned experimental configuration of non-equispaced tests performed on the real system, which were based on analysis characteristics. This discussion is the ideal extension of the basic case involving equispaced configurations. A summary is presented of the results obtained from the application of a 3X4 mixed level factorial experiment implemented with a discrete and stochastic industrial simulator.     

Decomposition of cumulative chi-squared statistics,with some new tools for their interpretation

It is well known that the Pearson statistic \(\chi ^{2}\) can perform poorly in studying the association between ordinal categorical variables. Taguchi’s and Hirotsu’s statistics have been introduced in the literature as simple alternatives to Pearson’s chi-squared test for contingency tables with ordered categorical variables. The aim of this paper is to shed new light on these statistics, stressing their interpretations and characteristics, providing in this way new and different interpretations of these statistics. Moreover, a theoretical scheme is developed showing the links between the different proposals and classes of cumulative chi-squared statistical tests, starting from a unifying index of heterogeneity, unalikeability and variability measures. Users of statistics may find it attractive to understand well the different proposals. Some decompositions of both statistics are also highlighted. This paper presents a case study of optimizing the polysilicon deposition process in a very large-scale integrated circuit, to identify the optimal combination of factor levels. It is obtained by means of the information coming from a correspondence analysis based on Taguchi’s statistic and regression models for binary dependent variables. A new optimal combination of factor levels is obtained, different from many others proposed in the literature for this data.     

A bayesian predictive approach to sequential search for an optimal dose: Parametric and nonparametric models

Summary This paper looks at a new approach to the problem of finding the maximal tolerated dose (or optimal dose, Eichhorn and Zacks, 1973) of certain drugs which in addition to their therapeutic effects have secondary harmful effects. The problem is investigated in a sequential setting from a Bayesian predictive approach. Search procedures are proposed for parametric and nonparametric models.     

Inequality indices and the starshaped principle of transfers

The evaluation of income distributions is usually based on the Pigou-Dalton (PD) principle which says that a transfer from any people to people who have less decreases economic inequality, i.e., increases the social evaluation index. We introduce two weaker principles of transfers which refer to a parameter θ. With the new principles, only those PD transfers increase the social evaluation index which take from the class of incomes above θ and give to the class below θ. The relative positions of individuals remain unchanged, and either no individual may cross the line θ (principle of transfers about θ) or some may do who have been situated next to it (starshaped principle of transfers at θ). θ may be a given constant, a function of mean income, or a quantile of the income distribution. The classes of indices which are consistent with these transfers are completely characterized, and examples are given.