Parametric vs. Nonparametric Estimation of an Equilibrium Search Model with Employer Heterogeneity

We demonstrate that non-monotone behaviour of the right tail of earnings density may lead to the fact that nonparametric estimation of the Bontemps et al. (2000) equilibrium search model with employer heterogeneity does not yield consistent estimates. We propose an easy way of checking whether the Bontemps et al. (2000) estimation procedure can be applied and review the robustness of the alternative strategy once the Bontemps et al. (2000) procedure is inapplicable. --

Visibility of Young's interference fringes: Scattered light from small ion crystals

We observe interference in the light scattered from trapped $^{40}$Ca$^+$ ion crystals. By varying the intensity of the excitation laser, we study the influence of elastic and inelastic scattering on the visibility of the fringe pattern and discriminate its effect from that of the ion temperature and wave-packet localization. In this way we determine the complex degree of coherence and the mutual coherence of light fields produced by individual atoms. We obtain interference fringes from crystals consisting of two, three and four ions in a harmonic trap. Control of the trapping potential allows for the adjustment of the interatomic distances and thus the formation of linear arrays of atoms serving as a regular grating of microscopic scatterers.Comment: Main text: 5 pages, 4 figures. Supplemental Material: 2pages, 1 figur

Records of digger wasps from Eastern Siberia and the Far East of Russia (Hymenoptera: Sphecidae, Crabronidae)

Informationen zur Verbreitung von 17 Arten der Sphecidae und 106 Arten der Crabronidae im Osten Sibiriens werden prasentiert. Erstfunde fur Ostsibirien sind Crossocerus (Crossocerus) tarsatus (Shuckard, 1837), Diodontus handlirschi Kohl, 1888, Gorytes albidulus (Lepeletier, 1832), Gorytes procrustes Handlirsch, 1888, Nysson interruptus (Fabricius, 1798), Oxybelus haemorrhoidalis Olivier, 1812 und Pemphredon lethifer (Shuckard, 1837). Erstfund fur den Fernen Osten ist Ectemnius (Ectemnius) guttatus (Vander Linden, 1829).Information is given on the distribution of 17 species of Sphecidae and 106 species of Crabronidae in Eastern Siberia and the Russian Far East. First records for Eastern Siberia are Crossocerus (Crossocerus) tarsatus (Shuckard, 1837), Diodontus handlirschi Kohl, 1888, Gorytes albidulus (Lepeletier, 1832), Gorytes procrustes Handlirsch, 1888, Nysson interruptus (Fabricius, 1798), Oxybelus haemorrhoidalis Olivier, 1812 and Pemphredon lethifer (Shuckard, 1837). First recorded from Far East is Ectemnius (Ectemnius) guttatus (Vander Linden, 1829)