Lifetime Uncertainty and Time Preference

Despite Fisher's (1930) psychological intuitions of and the formal treatment given by Yaari (1965, Review of Economic Studies 32, 137), the intertemporal model of choice is mainly a model with certain lifetime. The purpose of this paper is to reconsider this assumption, starting from a very simple two-period model of choice with lifetime uncertainty. We examine the comparative statics of the model at the first two orders and replace the concept of `pure time preference' by taking into account the subjective treatment of the probability of survival. This revised version was published online in June 2006 with corrections to the Cover Date.     

Valuation effects of corporate strategic transactions in the cleantech industry

This paper investigates capital market reactions to announcements of corporate strategic transactions in the clean technology, or cleantech, industry. Using the event study method in a multi-country setting, we exploit a dataset of 328 hand-collected announcements of mergers and acquisitions, joint ventures, and asset disposals that took place between 2001 and 2011. We provide strong evidence of significant wealth gains from cleantech deals. On average, cleantech companies earn significantly higher abnormal returns than non-cleantech companies, confirming the beneficial idiosyncrasies of the cleantech industry. These high premia are likely driven by government interventions that are believed to be a necessary pre-condition for development of clean technology. Alternatively, the premia are commanded by the acquisition of cutting-edge environmental innovations and the positive credibility spillover inherent in cleantech deals.     

Manaagement practices and employee attitudes: a longitudinal study spanning fifty years

This paper reports findings from a third consecutive study to re‐visit a steelworks that provided a classic elaboration of the industrial enterprise as a social system. The social system of the works in the 1950s (Scott et al., 1956) was used to explain the positive orientation of steelworkers to change. A later study of the plant in 1991 uncovered a remarkably similar positive orientation to change in the plant indicating a number of continuities (Blyton et al., 1996). Despite massive changes affecting the plant between the 1950s and the early 1990s, the social system of the works‐occupational structures and identities and management‐union relations‐were seen as having a continuing bearing on steelworkers’ attitudes to work in general, and their positive orientation to work change in particular. A third study of employee attitudes in the same plant in 1999 revealed important changes had occurred during the 1990s.     

Sequential Monte Carlo on large binary sampling spaces

A Monte Carlo algorithm is said to be adaptive if it automatically calibrates its current proposal distribution using past simulations. The choice of the parametric family that defines the set of proposal distributions is critical for good performance. In this paper, we present such a parametric family for adaptive sampling on high dimensional binary spaces. A practical motivation for this problem is variable selection in a linear regression context. We want to sample from a Bayesian posterior distribution on the model space using an appropriate version of Sequential Monte Carlo. Raw versions of Sequential Monte Carlo are easily implemented using binary vectors with independent components. For high dimensional problems, however, these simple proposals do not yield satisfactory results. The key to an efficient adaptive algorithm are binary parametric families which take correlations into account, analogously to the multivariate normal distribution on continuous spaces. We provide a review of models for binary data and make one of them work in the context of Sequential Monte Carlo sampling. Computational studies on real life data with about a hundred covariates suggest that, on difficult instances, our Sequential Monte Carlo approach clearly outperforms standard techniques based on Markov chain exploration.     

Estimation and selection procedures in regression: An L1 approach

The authors consider the problem of estimating a regression function go involving several variables by the closest functional element of a prescribed class _G that is closest to it in the L₁ norm. They propose a new estimator ? based on independent observations and give explicit finite sample bounds for the L₁distance between ?g and go. They apply their estimation procedure to the problem of selecting the smoothing parameter in nonparametric regression.     

Still more on the Tournament Equilibrium Set

Schwartz (Soc Choice Welfare 3:271–291, 1990) proposed a solution concept (the Tournament Equilibrium Set) for choosing from a tournament and stated some conjectures about this solution. Laffond et al. (Math Sci Hum 123:37–44, 1993) introduced further conjectures and showed the links between some of them. In this short note, we show that one of the conjectures stated by Schwartz (1990) is false. We also complete a result given in Laffond et al. (1993). I gratefully thank J.-F. Laslier for his remarks and for introducing me to this topic.     

A global risk assessment model for civil wars

In this study, we construct a multivariate model that assesses the risk of an outbreak of civil war in a country over a period of 5 years into the future. In addition to structural factors of state weakness, which have dominated the literature on civil war onset, this model includes repression of basic human rights to personal integrity – an important harbinger of wars to come – as an aspect of state behavior. Our aim is not to explore the causal factors of civil war onset, but to build a model that includes indicators that correlate with civil war outbreak and may be used to predict it. Based on two versions of the model – logit and neural network – out-of-sample risk assessments for three different time periods are generated and compared to the historical record of civil war outbreak during those years. In addition, the model’s ability to produce in-sample risk assessments over a 5-year period is tested. Finally, we compute truly predictive civil war risk assessments for all countries for which data are available, for the years 2008–2012. The analyses show that with a relatively simple model and based on publicly available data sources, meaningful civil war risk assessments can be computed. The quality of the predictions exceeds that of prominent studies, in which the risk of interstate war is assessed.     

Modelling of a thermomechanically coupled forming process based on functional outputs from a finite element analysis and from experimental measurements

In this paper, measurements from experiments and results of a finite element analysis (FEA) are combined in order to compute accurate empirical models for the temperature distribution before a thermomechanically coupled forming process. To accomplish this, Design and Analysis of Computer Experiments (DACE) is used to separately compute models for the measurements and the functional output of the FEA. Based on a hierarchical approach, a combined model of the process is computed. In this combined modelling approach, the model for the FEA is corrected by taking into account the systematic deviations from the experimental measurements. The large number of observations based on the functional output hinders the direct computation of the DACE models due to the internal inversion of the correlation matrix. Thus, different techniques for identifying a relevant subset of the observations are proposed. The application of the resulting procedure is presented, and a statistical validation of the empirical models is performed.     

Change in disability-free life expectancy for Americans 70 years old and older*

In this article, we examine changes in life expectancy free of disability using longitudinal data collected from 1984 through 2000 from two cohorts who composed the Longitudinal Studies of Aging I and II. Life expectancies with and without ADL and/or IADL disability are calculated using a Markov-based multistate life table approach. At age 70, disability-free life expectancy increased over a 10-year period by 0.6 of a year in the later cohort, which was the same as the increase in total life expectancy, both increases marginally statistically significant. The average length of expected life with IADL and ADL disability did not change. Changes in disability-free life expectancy resulted from decreases in disability incidence and increases in the incidence of recovery from disability across the two survey cohorts. Age-specific mortality among the ADL disabled declined significantly in the later cohort after age 80. Mortality for the IADL disabled and the nondisabled did not change significantly. Those with ADL disability at age 70 experienced substantial increases in both total life expectancy and disability-free life expectancy. These results indicate the importance of efforts both to prevent and delay disability and to promote recovery from disability for increasing life expectancy without disability. Results also indicate that while reductions in incidence and increases in recovery work to decrease population prevalence of disability, declining mortality among the disabled has been a force toward increasing disability prevalence.     

Uses of Management Control Tools in the Public Healthcare Sector

This study focuses on identifying the specific uses of management control tools in public organizations. This research is based on interviews with managers from 43 organizations in the healthcare sector. Data was analyzed and interpreted through the methodology proposed by Gioia et al. Organizational research methods, 16(1), 15-31, (2013). The different uses specified by managers of these organizations were compared with Henri’s work Accounting, organizations and society, 31(1), 77-103, (2006). Findings show matching elements, as well as differences in public sector specificities. This study ends with a discussion about the non-use of existing tools, the multi-uses of tools and the observable dichotomy between political and management uses.