Military Retention Incentives: Evidence from the Air Force Selective Reenlistment Bonus

The limited lateral entry and rigid pay structure for U.S. military personnel present challenges in retaining skilled individuals who have attractive options in the civilian labor market. One tool the services use to address this challenge is the Selective Reenlistment Bonus (SRB), which offers eligible personnel with particular skills a substantial cash bonus upon reenlistment. However, the sequential nature of the bonus offer and reenlistment process limits the ability to adjust manpower quickly, raising interest in research that estimates the effect of the SRB on retention. While this literature has acknowledged challenges including potential endogeneity of bonus levels, attrition, and reenlistment eligibility, many studies do not address these concerns adequately. This paper uses a comprehensive panel data set on Air Force enlisted personnel to estimate the effect of the SRB on retention rates. We exploit variation in bonus levels within skill groups, control for civilian labor market conditions, and model reenlistment eligibility to avoid common assumptions that lead to biased impact estimates. We find substantial heterogeneity in the effect of the bonus, with the largest effects on first-term service members and those whose skills have not historically received a substantial bonus. We also find evidence that the bonus affects the timing of reenlistment decisions in addition to their frequency

Infiltrating ductal and lobular breast carcinomas are characterised by different interrelationships among markers related to angiogenesis and hormone dependence

To obtain a more integrated understanding of the different breast cancer phenotypes and to investigate whether bio-molecular profiles can distinguish between specific histotypes, we explored the interrelations among several biologic variables indicative of, or related to, hormone dependence, proliferation and apoptosis control, and angiogenesis in ductal and lobular carcinomas, the most common histotypes. Oestrogen and progesterone receptors, tumour proliferative activity, the expression of cyclin A, p16ink4A, p27kip1, p21waf1, p53, bcl-2, and levels of vascular endothelial growth factor and hypoxia-inducible factor-1α (HIF-1α) were evaluated in 190 in ductal and 67 lobular carcinomas. Our findings support the hypothesis that in ductal and lobular carcinomas are two distinct, partially phenotypically unrelated entities, the latter being characterised by the presence of features indicative of differentiation such as oestrogen receptors, low proliferation and lack of p53 expression and associated with low vascular endothelial growth factor content compared to angiogenesis in ductal carcinomas. Conversely, no significant difference was found between lobular carcinomas and in ductal carcinomas considering the frequency distribution of PgR-positive cases, cyclin-dependent kinase inhibitors acting at the G1/S boundary, bcl-2 and HIF-1α protein expression. Although both generally defined as hormone responsive, in ductal and lobular carcinomas are also characterised by biologic patterns in which proteins related to hormone responsiveness, cell-cycle control, apoptosis and angiogenesis were differently associated. This finding suggests the need to refine breast cancer characterisation in order to provide detailed information about individual tumours, or subsets of tumours, that will help in defining optimal treatment approaches

Econometric analysis of regional labour productivity in US coal mines: 1950-1975

Changes in labour productivity can bring about economic growth or decline of a region. The factors that explain increases or decreases in labour productivity, if identified, can help policy makers control them so as to mitigate explosive changes in productivity and their concomitant effects on the utilisation of capital, employment, prices, welfare payments and social services. This paper attempts to identify these variables for five coal-producing regions in the US. Section 2 describes these regions, identifies the relevant variables and presents an econometric methodology of regression equations for underground and surface mines. These variables are the non-captive mines, continuous mining technologies in underground mines and medium- and large-sized power shovels and draglines in surface mines, capacity utilisation, accident rates and mining regulations. The literature on regional labour productivity is critically reviewed in Section 3 and it is concluded that none of the five available studies help in comparing inter-regional productivity of labour. Section 4 presents empirical results of equations estimated for underground and surface mines and concludes that the selected variables explained variation in labour productivity significantly. In particular, the results revealed that the regional variations in productivity were explained by technological changes, mine ownership and regulatory laws passed by the Federal and the State governments.

Forecasting the cost of energy conservation in the residential sector: 1980-2000

This paper attempts to analyse and forecast the cost of energy conservation in the residential sector to the year 2000. It postulates that costs of conservation will increase as investors in conservation progress from the least cost conservation technologies, such as attic insulation and storm doors and windows, to heat pumps and solar water heaters. The methodology is that of regression equations and the data are costs of twenty types of capital stocks and the associated quantities of energy conserved. The regression equations of annualised cost on annualised quantities of conservation had a good fit and statistically significant coefficients so that the costs were increasing with increased conservation. The elasticity of cost with respect to conservation was 2·13 so that an increase in conservation by 1 per cent will increase its cost by more than 2 per cent. The cost-effectiveness of conservation was determined by comparing the cost of conservation per million Btu with the cost of purchasing an equivalent quantity of energy. It was concluded that energy conservation was cost-effective because the cost was only $0·84 per million Btu compared with the cost of purchasing energy, which was from two to eight times for natural gas to electricity.

Forecasting the cost of energy conser vation in the transportation sector

This paper attempts to estimate and forecast the cost of energy conservation in the transportation sector to the year 2000. It stipulates conservation as a depleting resource industry so that the costs tend to increase as additional quantities of energy are conserved. The methodology is that of regression equations and the data are from the US Department of Transportation and the Department of Energy. The regressions of annual costs on corresponding annual quantities of conservation have a good fit and positive and statistically significant coefficients. Hence the theory of energy conservation as a depleting resource industry or that of increasing cost is vindicated. The elasticity of cost with respect to conservation is 1·12 so that an increase in conservation by 1 per cent tends to increase cost by 1·12 per cent.

Automobile fuel regulations: Direct benefit-cost analysis, 1981-1984

The object of this paper is to analyse economic efficiency and equity aspects of the auto-gasoline mileage regulations for 1981-1984. The paper uses data available from the US Department of Transportation to estimate both the direct benefits of gasoline and maintenance cost savings and the cost of compliance by the manufacturers. The direct benefit/cost ratios exceed unity and it is concluded that the regulations are cost-effective. The equity aspects are analysed by grouping families according to income groups in the Consumer Expenditure Survey data of the US Bureau of Labor Statistics. The analysis shows that lower income groups owning fewer cars derive fewer benefits, relative to upper income groups, from fuel economy regulations. Income compensating measures such as [`]fuel stamps' are suggested as a way of mitigating this inequity.