An adaptive sequential Monte Carlo method for approximate Bayesian computation

Approximate Bayesian computation (ABC) is a popular approach to address inference problems where the likelihood function is intractable, or expensive to calculate. To improve over Markov chain Monte Carlo (MCMC) implementations of ABC, the use of sequential Monte Carlo (SMC) methods has recently been suggested. Most effective SMC algorithms that are currently available for ABC have a computational complexity that is quadratic in the number of Monte Carlo samples (Beaumont et al., Biometrika 86:983?C990, 2009; Peters et al., Technical report, 2008; Toni et al., J.?Roy. Soc. Interface 6:187?C202, 2009) and require the careful choice of simulation parameters. In this article an adaptive SMC algorithm is proposed which admits a computational complexity that is linear in the number of samples and adaptively determines the simulation parameters. We demonstrate our algorithm on a toy example and on a birth-death-mutation model arising in epidemiology.     

Coming out strategies of lesbians and gays at work / Estrategias de coming out de personas lesbianas y gays en el trabajo

Abstract

In recent years there has been a great deal of social and legislative progress in the struggle against discrimination on grounds of sexual orientation. However, the coming out process in the workplace is still a crucial aspect in the lives of many lesbians and gays (LG). This study sets out to analyse the different strategies that Spanish LG adopt when revealing their sexual orientation at work by identifying the factors that facilitate or hinder this process. It also analyses the personal and organizational consequences of the strategies used in the coming out process. The study was carried out through in-depth interviews with 15 LG. Results show that the coming out strategies vary and are affected by different factors (e.g., characteristics of the colleagues, sector, etc.). Moreover, it confirmed that the coming out process (or its absence) can have consequences at different levels (e.g., relationships with colleagues, perception of organizational injustice, etc.).     

The State,the Market and Cultural Diversity

This essay compares the logic of states and the logic of markets in the management of cultural diversity. On the one hand, the economic logic of markets leads to an encouragement of a ‘soft’ cultural diversity associated with the marketing of exoticism in music, the arts and cuisine, for example. On the other hand, the liberal states are trapped between their willingness to recognize some form of diversity and their fear of seeing social cohesion harmed by this recognition. In other words, the essay applies Hollified's hypothesis about the liberal paradox in immigration policy to the sphere of cultural diversity in post-immigration situations.     

Comparability of the 6-min walk test using different test configurations

The 6-min walk test (6MWT) is a common component of fitness assessments of older adults; however, differing course configurations might affect 6MWT performance. It is unclear how comparable 2 different configurations are. To determine the comparability of 2 courses, 35 adults >65 years of age completed two 6MWT, once walking around a 20- by 5-yd outdoor rectangle and once on an indoor oval track (circumference 144.3 yd). Scores for the 2 tests were internally consistent (intraclass correlation coefficient = .95). The participants walked farther on the oval track than around the rectangle (639 +/- 19 vs. 582 +/- 16 yd; p < .0001), but responses to the rectangular configuration could be readily estimated using the equation 66.7 yd + 0.807 x (oval walking distance), R2 = .85. Thus, within-participant responses are similar across both 6MWT, but the course configuration affects the distance walked.     

Do conditional cash transfers influence migration? A study using experimental data from the Mexican progresa program

Prior research on Mexican migration has shown that social networks and economic incentives play an important role in determining migration outcomes. We use experimental data from PROGRESA, Mexico's primary poverty-reduction program, to evaluate the effects of conditional cash transfers on migration both domestically and to the United States. Our study complements a growing body of literature aimed at overcoming longstanding hurdles to the establishment of causal validity in empirical studies of migration. Analysis based on the data collected before and after the program's onset shows that conditional transfers reduce U.S. migration but not domestic migration. The data also enable us to explore the role of existing family and community migration networks. The results show that migration networks strongly influence migration, but that the effect of conditional transfers on migration is apparently not mediated by existing migration network structures. Our results suggest that conditional transfers may be helpful in managing rural out-migration, particularly to the United States.     

Changing Industrial Metabolism: Methods for Analysis

Research in the field of industrial metabolism traditionally has been focused on measuring and describing physical flows of economic systems. The metabolism of economic systems, however, changes over time, and measuring material flows is insufficient to understand this process. Understanding the relation between economic activities and material flows can help to unravel the socio-economic causes of these physical flows. Three issues are addressed: The importance of spatial scales and trade flows, empirical analysis of relations between economic development and material flows, and treatment of behaviour of and interactions between stakeholders. For each of these issues, methods for analysis are suggested.     

Stochastic Choice and Consideration Sets

We model a boundedly rational agent who suffers from limited attention. The agent considers each feasible alternative with a given (unobservable) probability, the attention parameter, and then chooses the alternative that maximizes a preference relation within the set of considered alternatives. We show that this random choice rule is the only one for which the impact of removing an alternative on the choice probability of any other alternative is asymmetric and menu independent. Both the preference relation and the attention parameters are identified uniquely by stochastic choice data.     

A routine-based framework implementing workload control to address recurring disturbances

Abstract

This research focuses on responsiveness in high variety manufacturing environments. To achieve it, the article proposes to develop Dynamic Response Capabilities (DRCs) of the manufacturing system defined as the abilities to readjust the planned operating parameters of workload, capacity, and lead time, in the wake of disturbances. To inform their development, built on the Workload Control theory, a routine-based framework is proposed. The framework supports an integrated approach for the implementation of adaptive decision-making routines for workload, capacity, and lead time readjustments at different stages in the order fulfilment process. Findings from two empirical cases show the appropriateness of the framework to develop and utilise DRCs in different settings of disturbances. Results of a simulation study, with one of the case companies, also shows the effectiveness of the framework to drive performance improvements in presence of recurring disturbances leading to demand variability.     

Family Composition and Remarriage in Pre-Transitional Italy: A Comparative Study

It is well known that timing and intensity of remarriage were strictly dependent upon demographic, socio-economic, cultural and legislative factors specific to each community. Thus, the aim of this paper is to compare the extent to which such factors may affect the remarriage patterns of three pre-transitional Italian populations that were different in many respects. By using micro-level data of the sharecropping communities of Casalguidi and Madregolo and the Alpine village of Treppo Carnico, we highlighted similarities and differences in the respective remarriage patterns, in particular, the far lower intensity in the mountain community with respect to the sharecropping ones. Our findings show that along with differences in the demographic system, household structure and land tenure, normative elements concerning widows and the dotal system could in part explain the differentials we found.

On disjoint (3t, 3, 1) cyclic difference families

We give a new and easier proof of the existence of a disjoint (3t  , 3, 1) cyclic difference family for every t>3$t>3$, first proved by Dinitz and Shalaby (2002). Our purely theoretical construction is still elementary but simpler and does not need to be checked by computer.