Earnings Instability and Tenure

We study the effect of tenure on earnings instability in Italy using the reforms of temporary employment contracts, which affected the average tenure of workers differentially across cohorts. We develop a model of earnings dynamics, and we exploit the variation of tenure and instability over time and across birth cohorts to estimate policy‐relevant parameters. Our results indicate that each year of tenure on the job reduces earnings instability by 11 percent; the drop is faster in the first three years of the match. Workers on a temporary contract have an earnings instability up to 100 percent higher than workers on a permanent contract.     

A NOTE ON THE EFFECTS OF EFFICIENCY CRITERIA AND PORTFOLIO SIZE ON CHARACTERISTICS OF EFFICIENT PORTFOLIOS*

Comparisons of the results of using alternative efficiency criteria for portfolio selection, while plentiful overseas, are seemingly scarce in Australia. Here, mean-variance efficient sets are compared with and found to be not too different from sets efficient according to second and third degree stochastic dominance. In examining the effect of increasing the number of securities allowed in each portfolio, it is found that the size of efficient sets of portfolios diminishes, as does the mean return and, most significantly, the variance of return for efficient portfolios.     

Knowledge management technology as a stage for strategic self-presentation: Implications for knowledge sharing in organizations

This article explores why it is often difficult for organizations to capture, store, and share employees' individually held expertise. Drawing on studies of the social construction of expertise and theories of transactive memory systems and self-presentation in computer-mediated environments, we argue that knowledge management technologies are not simple containers for the storage of expertise, but that they are stages upon which individuals enact performances of expertise. Through a longitudinal study of the work of IT technicians we show that users of a knowledge management technology strategically craft their own information entries to position themselves as experts vis-à-vis their coworkers. The data suggest that proactive self-presentations enacted by a few actors early on may spur reactive behaviors of strategic self-presentation across the organization. We explore implications of these findings for theories of transactive memory systems and technology use in organizations.     

Can risk aversion explain schooling attainments? Evidence from Italy

Using unique Italian panel data, in which individual differences in behavior toward risk are measured from answers to a lottery question, we investigate if (and to what extent) risk aversion can explain differences in schooling attainments. We formulate the schooling decision process as a reduced-form dynamic discrete choice, which we estimate flexibly. We analyze how grade transition from one level to the next varies with preference heterogeneity (risk aversion), parental human capital, socioeconomic variables and persistent unobserved (to the econometrician) heterogeneity. We find that differences in attitudes toward risk account for a modest portion of the probability of entering higher education.     

Retrospective analysis of patients with advanced or metastatic gastric cancer in Colombia

Abstract

Aims: To assess patient and disease characteristics, treatment patterns, and associated costs in patients with advanced or metastatic gastric cancer (A/MGC) in Colombia, in both the public and private hospitals.

Materials and methods: A total of 145 patients who had received first-line chemotherapy treatment (platinum analog and/or a fluoropyrimidine) and were followed for at least 3 months after the last administration of a first-line cytotoxic agent were eligible for inclusion. Case-report forms were elaborated based on the patients’ medical records from three Colombian hospitals. Estimates of treatment costs were calculated using unit costs from the participating hospitals.

Results: Of the 145 patients, more than half (64.83%) were male, 79.56% were diagnosed with metastatic stage IV disease (mean age = 58.14?years). Prior to MGC diagnosis, 31.71% of the patients being operated on received a total gastrectomy; 66.9% of the patients received a doublet therapy, of which 5-fluorouracil (5-FU) in combination with cisplatin was the standard treatment (14%), followed by combination with leucovorin (12%). Only around 10% of the patients responded to first-line treatment. Out of 41.38% of the patients who received a second-line treatment, 71.67% were still administered a platinum analog and/or fluoropyrimidine. During the follow-up period, 52% of the patients progressed and 20% achieved stable disease. Best supportive care mostly consisted of outpatient visits after last line-therapy (72.41%), palliative radiotherapy (18.6%), and surgery (37.2%).

Limitations and conclusions: Gastric cancer is one of the main causes of cancer-related death in Colombia, as most of the patients are diagnosed at an advanced stage, when prognosis is poor. Treatment patterns are highly heterogeneous. Second-line treatments were mostly initiated with paclitaxel, capecitabine, irinotecan, or cisplatin.     

Theoretical foundations for the study of sociomateriality

This paper compares two alternative theoretical foundations upon which the study of sociomateriality can be built: agential realism and critical realism. It begins by providing a brief overview of the sociomaterial perspective on organizational practices and considers why this perspective holds great appeal at this point in time. I then engage with Mutch's (2013) critique of the agential realist foundation upon which most current discussions of sociomateriality are constructed to highlight what practical problems are generated when authors attempt to map agential realism's philosophical discussion onto empirical phenomena. Next, I attempt to make explicit what Mutch leaves implicit in his paper: how building studies of sociomateriality on the theoretical foundation offered by critical realism can, potentially, overcome some of the practical problems created by a footing on agential realism. Finally, I push Mutch's arguments one step further to compare what practical consequences arise when researchers attempt to construct studies of sociomateriality on either of these two theoretical foundations. I suggest that there are important implications for what one can study, how one can study it, and how scholars can contribute to theory on technology and organizing based on the theoretical foundation they choose to build upon.     

Agglomerative tendencies in the distribution of populations

"The paper explores the role of accessibility to mutual contacts as an agglomeration force in the spatial distribution of population. The uniqueness conditions for the equilibrium solutions are analyzed in the static case, with the aid of mathematical programming embedding properties. A dynamic version in continuous time is then built, and conditions for instability of a globally stable equilibrium and appearance of multiple locally stable and unstable equilibria are stated. Finally, some implications for the geographical structure are discussed."