Generalized Multiplicative Domains and Quantum Error Correction

Given a completely positive map, we introduce a set of algebras that we refer to as its generalized multiplicative domains. These algebras are generalizations of the traditional multiplicative domain of a completely positive map and we derive a characterization of them in the unital, trace-preserving case, in other words the case of unital quantum channels, that extends Choi's characterization of the multiplicative domains of unital maps. We also derive a characterization that is in the same flavour as a well-known characterization of bimodules, and we use these algebras to provide a new representation-theoretic description of quantum error-correcting codes that extends previous results for unitarily-correctable codes, noiseless subsystems and decoherence-free subspaces.Comment: 14 page

Climbing the Job Ladder: New Evidence of Gender Inequity

An explanation for the gender wage gap is that women are less able or less willing to 'climb the job ladder.' However, the empirical evidence on gender differences in job mobility has been mixed. Focusing on a subsample of younger, university-educated workers from an Australian longitudinal survey, we find strong evidence that the dynamics of promotions and employer changes worsen women's labour market position.wage gap, job changes, promotions, gender

The Dyke Marsh Preserve Ecosystem

For over a century, Dyke marsh along the Potomac River just south of Alexandria, VA, has been a favorite site for natural history studies. Despite earlier attempts at diking to create agricultural land and dredging for sand and gravel, the remaining marsh represents the last major tidal freshwater wetland on the upper Potomac River, and is now owned and maintained by the National Park Service as the Dyke Marsh Preserve. In the present paper historical data on physical properties and biota are compared and contrasted with more recent biological investigations to show functioning ecosystem components, interrelationships among the flora and fauna, and documented changes in biotic communities over the years. As a haven for migratory waterfowl and shorebirds, unique plant communities, and large, dynamic insect and vertebrate populations, the Preserve is constantly threatened by river pollution, nearby large-scale development projects, and bridge construction. The long-term stability of this unique Preserve depends largely on the vigilance of the Park Service, concerned citizens, and environmental groups to ensure the preservation of this valuable functioning ecosystem

Evidence on the Long Shadow of Poor Mental Health across Three Generations

Individuals suffering from mental health problems are often severely limited in their social and economic functioning. Mental health problems can develop early in life, are frequently chronic in nature, and have an established hereditary component. The extent to which mental illness runs in families could therefore help explain the widely discussed intergenerational transmission of socioeconomic disadvantage. Using data from three generations contained in the 1970 British Cohort Study, we estimate the intergenerational correlation of mental health between mothers, their children, and their grandchildren. We find that the intergenerational correlation in mental health is about 0.2, and that the probability of feeling depressed is 63 percent higher for children whose mothers reported the same symptom 20 years earlier. Moreover, grandmother and grandchild mental health are strongly correlated, but this relationship appears to work fully through the mental health of the parent. Using grandmother mental health as an instrument for maternal mental health in a model of grandchild mental health confirms the strong intergenerational correlation. We also find that maternal and own mental health are strong predictors of adulthood socioeconomic outcomes. Even after controlling for parental socioeconomic status, own educational attainment, and own mental health (captured in childhood and adulthood), our results suggest that a one standard deviation reduction in maternal mental health reduces household income for their adult offspring by around 2 percent.intergenerational transmission, mobility, mental health, economic outcomes

Destined for (Un)Happiness: Does Childhood Predict Adult Life Satisfaction?

In this paper we address the question of how much of adult life satisfaction is predicted by childhood traits, parental characteristics and family socioeconomic status. Given the current focus of many national governments on measuring population well-being, and renewed focus on effective policy interventions to aid disadvantaged children, we study a cohort of children born in a particular week in 1958 in Britain who have been repeatedly surveyed for 50 years. Importantly, at four points in their adult lives this cohort has been asked about their life satisfaction (at ages 33, 42, 46, and 50). A substantive finding is that characteristics of the child and family at birth predict no more than 1.2% of the variance in average adult life satisfaction. A comprehensive set of child and family characteristics at ages 7, 11 and 16 increases the predictive power to only 2.8%, 4.3% and 6.8%, respectively. We find that the conventional measures of family socioeconomic status, in the form of parental education, occupational class and family income, are not strong predictors of adult life satisfaction. However, we find robust evidence that non-cognitive skills as measured by childhood behavioural-emotional problems, and social maladjustment, are powerful predictors of whether a child grows up to be a satisfied adult. We also find that some aspects of personality are important predictors. Adding contemporaneous adulthood variables for health and socio-economic status increases the predictability of average life satisfaction to 15.6%, while adding long-lags of life satisfaction increases the predictive power to a maximum of 35.5%. Repeating our analyses using data from the 1970 British Cohort Study confirms our main findings. Overall, the results presented in the paper point to average adult life satisfaction not being strongly predictable from a wide-range of childhood and family characteristics by age 16, which implies that there is high equality of opportunity to live a satisfied life, at least for individuals born in Britain in 1958 and 1970.childhood, socioeconomic status, life satisfaction, non-cognitive, cognitive

Mental Health and Labour Market Participation: Evidence from IV Panel Data Models

A large body of empirical research links mental health and labour market outcomes; however, there are few studies that effectively control for the two-way causality between work and health and the existence of unobserved individual characteristics that might jointly determine health and labour market outcomes. In this study, we estimate the effect of mental health on labour market participation using various models, including instrumental variable models that exploit individual variation observed in panel data. We find robust evidence that a reduction in mental health has a substantial negative impact on the probability of actively participating in the labour market. We calculate that a one standard deviation decrease in mental health decreases the probability of participation by around 17 percentage points. This effect is larger for females and for older individuals. We therefore provide robust evidence that there are substantial costs due to the lost productivity resulting from poor mental health.measurement error, mental health, labour market participation, causality