Passive solar reflector satellite revisited

Passive light weight reflectors in space which direct the incident solar energy to a specified location on the Earth surface are proposed as an alternative system for the solar power satellite to overcome conversion losses and to avoid the need for photovoltaic cells. On Earth, either photovoltaic cells or a steam turbine alternator on a solar tower, or a similar conventional, relatively high efficiency cycle are used for electricity generation. The constraints which apply to the design of the optical system if a single satellite is placed in geostationary orbit are outlined. A single lens and a two lens system are discussed

Keeping up with the Joneses and staying ahead of the Smiths: evidence from suicide data

This paper empirically assesses the theory of interpersonal income comparison using a unique data set on suicide deaths in the United States. We treat suicide as a choice variable, conditional on exogenous risk factors, reflecting one's assessment of current and expected future utility. Using this framework we examine whether differences in group-specific suicide rates are systematically related to income dispersion, controlling for socio-demographic characteristics and income level. The results strongly support the notion that individuals consider relative income in addition to absolute income when evaluating their own utility. Importantly, the findings suggest that relative income affects utility in a two-sided manner, meaning that individuals care about the incomes of those above them (the Joneses) and those below them (the Smiths). Our results complement and extend those from studies using subjective survey data or data from controlled experiments.Income distribution

Happiness, unhappiness, and suicide: an empirical assessment

The use of subjective well-being (SWB) data for investigating the nature of individual preferences has increased tremendously in recent years. There has been much debate about the cross-sectional and time series patterns found in these data, particularly with respect to the relationship between SWB and relative status. Part of this debate concerns how well SWB data measures true utility or preferences. In a recent paper, Daly, Wilson, and Johnson (2007) propose using data on suicide as a revealed preference (outcome-based) measure of well-being and find strong evidence that reference-group income negatively affects suicide risk. In this paper, we compare and contrast the empirical patterns of SWB and suicide data. We find that the two have very little in common in aggregate data (time series and cross-sectional), but have a strikingly strong relationship in terms of their determinants in individual-level, multivariate regressions. ; This latter result cross-validates suicide and SWB micro data as useful and complementary indicators of latent utility.Happiness ; Suicide

How Working age People with Disabilities Fared over the 1990s Business Cycle

Using data from the March Current Population Survey (CPS) we show that while the longest peacetime economic expansion in United States history has increased the economic well-being of most Americans, the majority of working age men and women with disabilities have been left behind. Robust economic growth since the recession of the early 1990s has lifted nearly all percentiles of the income distribution of working age men and men without disabilities beyond their previous business cycle peak levels of 1989. In contrast, the majority of working age men and women with disabilities did not share in economic growth over this period. Not only did their employment and labor earnings fall during the recession of the early 1990s but their employment and earnings continued to fall during the economic expansion that followed

Relative status and well-being: evidence from U.S. suicide deaths

This paper empirically assesses the theory of interpersonal income comparison using individual level data on suicide deaths in the United States. We model suicide as a choice variable, conditional on exogenous risk factors, reflecting an individual's assessment of current and expected future utility. Our empirical analysis considers whether suicide risk is systematically related to the income of others, holding own income and other individual factors fixed. We estimate proportional hazards and probit models of the suicide hazard using two separate and independent data sets: (1) the National Longitudinal Mortality Study and (2) the Detailed Mortality Files combined with the 5 percent Public Use Micro Sample of the 1990 decennial census. Results from both data sources show that, controlling for own income and individual characteristics, individual suicide risk rises with reference group income. This result holds for reference groups defined broadly, such as by county, and more narrowly by county and one demographic marker (e.g., age, sex, race). These findings are robust to alternative specifications and cannot be explained by geographic variation in cost of living, access to emergency medical care, mismeasurement of deaths by suicide, or by bias due to endogeneity of own income. Our results confirm findings using self-reported happiness data and are consistent with models of utility featuring "external habit" or "Keeping Up with the Joneses" preferences.Income distribution ; Suicide

Economics of Disability Research Report #5: Economic Outcomes of Working-Age People with Disabilities over the Business Cycle – an Examination of the 1980s and 1990s

We examine the rate of employment and the household income of the working-age population (aged 25-61) with and without disabilities over the business cycles of the 1980s and 1990s using data from the March Current Population Survey and the National Health Interview Survey. In general, we find that while the employment of working-age men and women with and without disabilities exhibited a procyclical trend during the 1980s business cycle, this was not the case during the 1990s expansion. During the 1990s, the employment of working-age men and women without disabilities continued to be procyclical, but the employment rates of their counterparts with disabilities declined over the entire 1990s business cycle. Although increases in disability transfer income replaced a significant fraction of their lost earnings, the household income of men and women with disabilities fell relative to the rest of the population over the decade

Self-Reported Work Limitation Data: What They Can and Cannot Tell Us

Data constraints make the long-term monitoring of the working-age population with disabilities a difficult task. Indeed, the Current Population Survey (CPS) is the only national data source that offers detailed work and income questions and consistently asked measures of disability over a 20-year period. Despite its widespread use in the literature, the CPS and surveys like it have come under attack of late, with critics discounting the results of any research obtained from such data. We put these criticisms in perspective by systematically examining what the CPS data can and cannot be used for in disability research. Based on comparisons with the National Health Interview Survey (NHIS), a data set with much more information on health than the CPS, we find that the work limitation-based definition of disability available in the CPS underestimates the size of the broader population with health impairments in the NHIS, but that the employment trends in these two populations in the NHIS are not significantly different from one another. We then show that the trends in employment observed for the NHIS population defined by self-reported work limitation are not statistically different from those found in the CPS. Based on these findings, we argue (1) that the CPS and other nationally representative employment-based data sets can be used to monitor trends in outcomes of those with disabilities and, (2) that the dramatic decline in the employment of people with disabilities we describe in the CPS during the 1990s is not an artifact of the data

Dry Friction due to Adsorbed Molecules

Using an adiabatic approximation method, which searches for Tomlinson model-like instabilities for a simple but still realistic model for two crystalline surfaces in the extremely light contact limit, with mobile molecules present at the interface, sliding relative to each other, we are able to account for the virtually universal occurrence of "dry friction." The model makes important predictions for the dependence of friction on the strength of the interaction of each surface with the mobile molecules.Comment: four pages of latex, figure provide

The happiness - suicide paradox

Suicide is an important scientific phenomenon. Yet its causes remain poorly understood. This study documents a paradox: the happiest places have the highest suicide rates. The study combines findings from two large and rich individual-level data sets—one on life satisfaction and another on suicide deaths—to establish the paradox in a consistent way across U.S. states. It replicates the finding in data on Western industrialized nations and checks that the paradox is not an artifact of population composition or confounding factors. The study concludes with the conjecture that people may find it particularly painful to be unhappy in a happy place, so that the decision to commit suicide is influenced by relative comparisons.Happiness ; Suicide