Let's (not) talk about sex: The effect of information provision on gender differences in performance under competition

We study how gender differences in performance under competition areaffected by the provision of information regarding rival s gender and/ordifferences in relative ability. In a laboratory experiment, we use two tasks thatdiffer regarding perceptions about which gender outperforms the other. Weobserve women s underperformance only under two conditions: 1) tasks areperceived as favoring men and 2) rivals gender is explicitly mentioned. Thisresult can be explained by stereotype-threat being reinforced when explicitlymentioning gender in tasks in which women already consider they are inferior.Omitting information about gender is a safe alternative to avoid women sunderperformance in competition.

Productivity and the welfare of nations

We show that the welfare of a representative consumer can be related to observable aggregatedata. To a first order, the change in welfare is summarized by (the present value of) the Solowproductivity residual and by the growth rate of the capital stock per capita. We also show thatproductivity and the capital stock suffice to calculate differences in welfare across countries, withboth variables computed as log level deviations from a reference country. These results hold forarbitrary production technology, regardless of the degree of product market competition, and applyto open economies as well if TFP is constructed using absorption rather than GDP as the measureof output. They require that TFP be constructed using prices and quantities as perceived byconsumers. Thus, factor shares need to be calculated using after-tax wages and rental rates, andwill typically sum to less than one. We apply these results to calculate welfare gaps and growthrates in a sample of developed countries for which high-quality TFP and capital data are available.We find that under realistic scenarios the United Kingdom and Spain had the highest growth ratesof welfare over our sample period of 1985-2005, but the United States had the highest level ofwelfare.

Sex differences in the neurobiology of fear conditioning and extinction: a preliminary fMRI study of shared sex differences with stress-arousal circuitry.

BACKGROUND: The amygdala, hippocampus, medial prefrontal cortex (mPFC) and brain-stem subregions are implicated in fear conditioning and extinction, and are brain regions known to be sexually dimorphic. We used functional magnetic resonance imaging (fMRI) to investigate sex differences in brain activity in these regions during fear conditioning and extinction. METHODS: Subjects were 12 healthy men comparable to 12 healthy women who underwent a 2-day experiment in a 3 T MR scanner. Fear conditioning and extinction learning occurred on day 1 and extinction recall occurred on day 2. The conditioned stimuli were visual cues and the unconditioned stimulus was a mild electric shock. Skin conductance responses (SCR) were recorded throughout the experiment as an index of the conditioned response. fMRI data (blood-oxygen-level-dependent [BOLD] signal changes) were analyzed using SPM8. RESULTS: Findings showed no significant sex differences in SCR during any experimental phases. However, during fear conditioning, there were significantly greater BOLD-signal changes in the right amygdala, right rostral anterior cingulate (rACC) and dorsal anterior cingulate cortex (dACC) in women compared with men. In contrast, men showed significantly greater signal changes in bilateral rACC during extinction recall. CONCLUSIONS: These results indicate sex differences in brain activation within the fear circuitry of healthy subjects despite similar peripheral autonomic responses. Furthermore, we found that regions where sex differences were previously reported in response to stress, also exhibited sex differences during fear conditioning and extinction.

Hommes et femmes: sommes-nous tous égaux face à la douleur [Are there differences between men and women with pain?].

An increasing number of articles are published on the differences about pain in men and women. These differences seem to be due to the sex, the biological dimension of the person, and to the gender, which is the role given to that person in a given social and culture environment. The pain prevalence is higher in women, its threshold and tolerance are lower. The pain interpretation, its perception and the coping is also different in men and women. Finally doctors translate and treat pain differently. This article proposes some explanations on these differences which should help us to treat this frequent and noxious symptom for the quality of life in a better way.

Twitch and M-wave potentiation induced by intermittent maximal voluntary quadriceps contractions: Differences between direct quadriceps and femoral nerve stimulation.

Introduction: To investigate differences in twitch and M-wave potentiation in the quadriceps femoris when electrical stimulation is applied over the quadriceps muscle belly versus the femoral nerve trunk. Methods: M-waves and mechanical twitches were evoked using direct quadriceps muscle and femoral nerve stimulation between 48 successive isometric maximal voluntary contractions (MVC) from 10 young, healthy subjects. Potentiation was investigated by analyzing the changes in M-wave amplitude recorded from the vastus medialis (VM) and vastus lateralis (VL) muscles and in quadriceps peak twitch force. Results: Potentiation of twitch, VM M-wave, and VL M-wave were greater for femoral nerve than for direct quadriceps stimulation (P<0.05). Despite a 50% decrease in MVC force, the amplitude of the M-waves increased significantly during exercise. Conclusions: In addition to enhanced electrogenic Na(+) -K(+) pumping, other factors (such as synchronization in activation of muscle fibers and muscle architectural properties) might significantly influence the magnitude of M-wave enlargement. © 2013 Wiley Periodicals, Inc.

To use it or not to use it: differences between adolescent males carrying a weapon and those using it in a fight

Purpose Data indicate that 19% of male adolescents living in Switzerland carried a weapon in the last 12 months. The main objective of this research is to compare the characteristics of male adolescents carrying a weapon and having used it in a fight from those who have carried but not used it in the previous 12 months. Methods Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health (SMASH02) data base, a survey including 7,548[3,710 males] in-school adolescents aged 16-20 years in Switzerland. Only males declaring having carried a weapon (N = 711; 19.2% of the sample) were included in the analysis. Three groups were created: those not having used a weapon (WO; N = 538 subjects), those having used a weapon in a fight once or twice (W12; N = 127), and those having used a weapon in a fight 3 or more times (W3+; N = 46). Multinomial logistic regression was performed to compare the 3 groups on individual, family, school, and social factors using WO as the reference category. Analyses were performed with STATA9. Results are presented as relative risk ratios (RRR). Results W12 males were significantly more likely to perceive their puberty as advanced compared to their peers (RRR: 2.1), to be foreign born (RRR: 2.6), to live in an urban environment (RRR: 1.9), to be in vocational school (RRR: 4.7), to have a poor school connectedness (RRR: 1.8), to skip classes (RRR: 2.1) and to quarrel while intoxicated (RRR: 5.3). W3+ males were significantly more likely to be foreign born (RRR: 3.6) and to live in an urban environment (RRR: 2.4), to be current users of illegal drugs other than cannabis (RRR: 3.8) and to quarrel while intoxicated (RRR: 4.1). No differences were found between groups for tobacco, alcohol, or cannabis use. Conclusions Within a national sample of Swiss youth aged 16-20 years, almost one fifth of male adolescents have carried a weapon in the previous 12 months. Nevertheless, most of them (75.7%) have never used a weapon in a fight. Whether they carry a weapon for defense purposes or as a manly behavior remains to be elucidated. However, urban foreign-born adolescents who quarrel while intoxicated are the most at risk of using a weapon in a fight, and therefore culturally-sensitive prevention approaches need to be developed to decrease violence in this specific population of youth. Having school problems or using illegal drugs other than cannabis seem to differentiate between those who use it in a fight occasionally (once or twice) and those who do it more often.

How wide is the gap? An investigation of gender wage differences using quantile regression

In this paper we examine the determinants of wages and decompose theobserved differences across genders into the "explained by differentcharacteristics" and "explained by different returns components"using a sample of Spanish workers. Apart from the conditionalexpectation of wages, we estimate the conditional quantile functionsfor men and women and find that both the absolute wage gap and thepart attributed to different returns at each of the quantiles, farfrom being well represented by their counterparts at the mean, aregreater as we move up in the wage range.

Why do differences in the degree of fiscal decentralization endure?

A notable difference between the U.S. and many countries in Europe is in the degree of fiscal decentralization. Regional (and local) governments in the U.S. have significant autonomy in setting their own taxes and determining how to spend their revenues. This is not true of their counterparts in Spain, France, the United Kingdom, Czech Republic and many other European countries. In recent years, many countries formerly subject to dictatorshipsor communism have been considering decentralizing fiscal responsibility to sub-national governments as part of the process of democratization (see Bird and Ebel, forthcoming). Yet, much of Europe remains immune to adopting effective decentralization in which sub-national units have true taxing authority.

Regional differences in socio-economic health inequalities in Spain

This paper reports an analysis of income related health inequalities at the AutonomousCommunity level in Spain using the self assessed health measure in the 2001 edition of theEncuesta Nacional de Salud. We use recently developed methods in order to cardinalise andmodel self assessed health within a regression framework, decompose the sources ofinequality and explain the observed differences across regions. We find that the regions with the highest levels of mean health tend to enjoy the lowest degrees of income related health inequality and vice-versa. The main feature characterizing regions where income related health inequality is low is the absence of a positive gradient between income and health. In turn, the regions where income related health inequality is greater are characterized by a strong and significant positive gradient between health and income. These results suggest that policies aimed at eliminating the gradient between health and income can potentially lead to greate r reductions in socio-economic health inequalities than policies aimed at redistributing income.