FUSE, STIS, and Keck spectroscopic analysis of the UV-bright star vZ 1128 in M3 (NGC 5272)

We present a spectral analysis of the UV-bright star vZ 1128 in M3 based on observations with the Far Ultraviolet Spectroscopic Explorer (FUSE), the Space Telescope Imaging Spectrograph (STIS), and the Keck HIRES echelle spectrograph. By fitting the H I, He I, and He II lines in the Keck spectrum with non-LTE H-He models, we obtain Teff = 36,600 K, log g = 3.95, and log N(He)/N(H) = -0.84. The star's FUSE and STIS spectra show photospheric absorption from C, N, O, Al, Si, P, S, Fe, and Ni. No stellar features from elements beyond the iron peak are observed. Both components of the N V 1240 doublet exhibit P~Cygni profiles, indicating a weak stellar wind, but no other wind features are seen. The star's photospheric abundances appear to have changed little since it left the red giant branch (RGB). Its C, N, O, Al, Si, Fe, and Ni abundances are consistent with published values for the red-giant stars in M3, and the relative abundances of C, N, and O follow the trends seen on the cluster RGB. In particular, its low C abundance suggests that the star left the asymptotic giant branch before the onset of third dredge-up.Comment: 15 pages, 10 figures, to be published in MNRA

Marginal Taxes: A Good or a Bad for Wages?: The Incidence of the Structure of Income and Labor Taxes on Wages

Empirical evidence so far found ambiguous results for the direction of effect of marginal income tax rates on employee remuneration. Based on the GSOEP data from 2002 through 2008 this study analyzes the impact of the marginal tax load on the employee side on the wage rate also allowing average tax rates and employer payroll taxes to play a role. Instrumental variable estimation based on counterfactual tax rates simulated in a highly detailed microsimulation model (STSM) heals the endogeneity problem of the tax variables with regard to wages. Estimations in first differences show that marginal taxes overall have a negative impact on wages. But this effect is not uniform along the wage distribution; while the negative effect of marginal tax rates prevails in the lower part of the distribution, observations beyond the median benefit from higher tax rates at the margin

Public health insurance and entry into self-employment

We estimate the impact of a differential treatment of paid employees versus self-employed workers in a public health insurance system on the entry rate into entrepreneurship. In Germany, the public health insurance system is mandatory for most paid employees, but not for the selfemployed, who usually buy private health insurance. Private health insurance contributions are relatively low for the young and healthy, and until 2013 also for males, but less attractive at the other ends of these dimensions and if membership in the public health insurance allows other family members to be covered by contribution-free family insurance. Therefore, the health insurance system can create incentives or disincentives to starting up a business depending on the family’s situation and health. We estimate a discrete time hazard rate model of entrepreneurial entry based on representative household panel data for Germany, which include personal health information, and we account for non- random sample selection. We estimate that an increase in the health insurance cost differential between self-employed workers and paid employees by 100 euro per month decreases the annual probability of entry into selfemployment by 0.38 percentage points, i.e. about a third of the average annual entry rate. The results show that the phenomenon of entrepreneurship lock, which an emerging literature describes for the system of employer provided health insurance in the USA, can also occur in a public health insurance system. Therefore, entrepreneurial activity should be taken into account when discussing potential health care reforms, not only in the USA and in Germany

Optimal taxation under different concepts of justness

A common assumption in the optimal taxation literature is that the social planner maximizes a welfarist social welfare function with weights decreasing with income. However, high transfer withdrawal rates in many countries imply very low weights for the working poor in practice. We reconcile this puzzle by generalizing the optimal taxation framework by Saez (2002) to allow for alternatives to welfarism. We calculate weights of a social planners function as implied by the German tax and transfer system based on the concepts of welfarism, minimum absolute and relative sacrifice, as well as subjective justness. For the latter we use a novel question from the German Socio-Economic Panel. We find that the minimum absolute sacrifice principle is in line with social weights that decline with net income. Absolute subjective justness is roughly in line with decreasing social weights, which is reflected by preferences of men, West Germans, and supporters of the grand coalition parties