The Long-term Effects of Early Track Choice

We investigate the effects of attending a more advanced track in middle school on long-term education and labour market outcomes for Germany, a country with a rigorous early-age tracking system, where the risk of misallocating students is particularly high. Our research design exploits quasi-random shifts between tracks induced by date of birth, and speaks to the long-term effects of early track attendance for a group of marginal students most at risk of misallocation. Remarkably, we find no evidence that attending a more advanced track leads to more favourable long-term outcomes. We attribute this result to the possibility of later track-reversal

Spillover Effects of Mass Layoffs

Using administrative data on firms and workers in Germany, we quantify the spillover effects of mass layoffs. Our empirical strategy combines matching with an event study approach to trace employment and wages in regions hit by a mass layoff relative to suitable control regions. We find sizable and persistent negative spillover effects on the regional economy: regions, and especially firms producing in the same broad industry as the layoff plant, lose many more jobs than in the initial layoff. In contrast, negative employment effects on workers employed in the region at the time of the mass layoff are considerably smaller. Strikingly, workers younger than 50 suffer no employment losses, as geographic mobility fully shields them from the decline in local employment opportunities

How Do Firms Respond to Place-Based Tax Incentives?

In this paper, we evaluate the effects of payroll tax changes on firm behavior, by exploiting a unique policy setting in Norway, where a system of geographically differentiated payroll taxes was suddenly abolished due to an EU regulation. We find that firms are only partially able to shift the increased costs from higher payroll tax rates onto workers’ wages. Instead, firms respond to the tax increase primarily by reducing employment. The drop in employment following the tax reform is particularly pronounced in labor intensive firms—which experience a larger windfall loss due to the tax reform than non-labor intensive firms—and in multi-establishment firms—which respond to the payroll tax increase in part by reducing the number of establishments per firm. Overall, our findings point to liquidity effects whereby a sudden and largely unexpected payroll tax increase aggravates firms’ liquidity constraints, forcing them to cut employment to bring down costs

Along- and Across-Arc Variations in the Southern Volcanic Zone, Chile

Within Collaborative Research Center (SFB574), we are studying the changes in the chemistry of olivinebearing volcanic rocks along the volcanic front of the Southern Volcanic Zone (SVZ) in Chile and in the rear and backarc in Argentina. Samples from the volcanic front (VF) have typical trace element signatures of subduction zone volcanic rocks, characterized, for example, by negative Nb and Ta anomalies and positive Pb, Sr, Cs, Rb, Ba, Th and U anomalies on incompatible element (spider) diagrams. Samples from Longavi in the forearc are distinct in having lower abundances of the HREE's, high Sr/Y and geochemical signatures characteristic of adakitic rocks believed to be derived through melting of the subducting slab. The northern Southern Volcanic Zone (NSVZ) samples from Tupungatito and San José have the most enriched highly to moderately incompatible element ratios, high Rb/Ba and low La/Ta and Ba/La, suggesting involvement of lower crust in the petrogenesis of these rocks. We observe systematic variations in Sr and Nd isotopic compositions along the arc, with Sr isotopes showing a dramatic increase and Nd isotopes showing a dramatic decrease in the NSVZ, which is where the crust begins to thicken significantly. The increase in Sr and decrease in Nd in the VF is coupled with an increase in the degree of differentiation of the Tupungatito and San José (SiO2 > 58%, MgO = 2-4%) volcanoes. On the Pb isotope diagrams, the VF rocks trend from MORB-like compositions to the field for pelagic sediments, consistent with involvement of subducted sediments in generating the VF rocks. Interestingly, samples from the NSVZ form the lower end of the VF array (have the least radiogenic Pb isotopic compositions) on the uranogenic Pb isotope diagram, but extend to the left of the rest of the VF array on the thorogenic Pb isotope diagram, showing evidence of at least a second enriched component. The presence of the second enriched component could reflect assimilation of lower crust or addition of lower crust through subduction erosion into the manlte wedge. Quaternary backarc samples in Argentina also show subduction signatures in their incompatible elements but generally show lower fluid signatures than the VF samples. Although the Pb isotopic compositions of backarc rocks are similar to MORB, the low Nd isotopic compositions indicate the presence of enriched material within the backarc. Although no systematic variation is seen in Sr and Nd isotopic composition from north to souths, the Pb isotope ratios show systematic spatial variations with the northern samples having the most enriched Pb isotope ratios. The lower fluid signatures in the backarc volcanoes, coupled with less radiogenic Pb isotopic compositions are consistent with a decreasing influence of the subduction signature into the backarc. With the addition of Hf and O isotope data we should be able to better constrain the different reservoirs involved in generating the diverse geochemical compositions of the SVZ volcanic rocks

Reallocation Effects of the Minimum Wage

We investigate the wage, employment and reallocation effects of the introduction of a nationwide minimum wage in Germany that affected 15% of all employees. Based on identification designs that exploit variation in exposure across individuals and local areas, we find that the minimum wage raised wages, but did not lower employment. It also led to the reallocation of low-wage workers from smaller to larger, from lower- to higher-paying, and from less- to more-productive establishments. This worker upgrading accounts for up to 17% of the wage increase induced by the minimum wage. Moreover, at the regional level, average establishment quality increased in more affected areas in the years following the introduction of the minimum wage

Origin of fluids and anhydrite precipitation at the sediment-hosted Grimsey hydrothermal field north of Iceland

The sediment-hosted Grimsey hydrothermal field is situated in the Tjörnes fracture zone (TFZ) which represents the transition from northern Iceland to the southern Kolbeinsey Ridge. The TFZ is characterized by a ridge jump of 75 km causing widespread extension of the oceanic crust in this area. Hydrothermal activity occurs in the Grimsey field in a 300 m×1000 m large area at a water depth of 400 m. Active and inactive anhydrite chimneys up to 3 meters high and hydrothermal anhydrite mounds are typical for this field. Clear, metal-depleted, up to 250 °C hydrothermal fluids are venting from the active chimneys. Anhydrite samples collected from the Grimsey field average 21.6 wt.% Ca, 1475 ppm Sr and 3.47 wt.% Mg. The average molar Sr/Ca ratio is 3.3×10−3. Sulfur isotopes of anhydrite have typical seawater values of 22±0.7‰ δ34S, indicating a seawater source for SO42−. Strontium isotopic ratios average 0.70662±0.00033, suggesting the precipitation of anhydrite from a hydrothermal fluid–seawater mixture. The endmember of the venting hydrothermal fluids calculated on a Mg-zero basis contains 59.8 μmol/kg Sr, 13.2 mmol/kg Ca and a 87Sr/86Sr ratio of 0.70634. The average Sr/Ca partition coefficient between the hydrothermal fluids and anhydrite of about 0.67 implies precipitation from a non-evolved fluid. A model for fluid evolution in the Grimsey hydrothermal field suggests mixing of upwelling hydrothermal fluids with shallowly circulating seawater. Before and during mixing, seawater is heated to 200–250 °C which causes anhydrite precipitation and probably the formation of an anhydrite-rich zone beneath the seafloor

Post-Collisional Transition from Subduction to Intraplate-type Magmatism in the Westernmost Mediterranean: Evidence for Continental-Edge Delamination of Subcontinental Lithosphere

Post-collisional magmatism in the southern Iberian and northwestern African continental margins contains important clues for the understanding of a possible causal connection between movements in the Earth's upper mantle, the uplift of continental lithosphere and the origin of circum-Mediterranean igneous activity. Systematic geochemical and geochronological studies (major and trace element, Sr–Nd–Pb-isotope analysis and laser 40Ar/39Ar-age dating) on igneous rocks provide constraints for understanding the post-collisional history of the southern Iberian and northwestern African continental margins. Two groups of magmatic rocks can be distinguished: (1) an Upper Miocene to Lower Pliocene (8·2–4·8 Ma), Si–K-rich group including high-K (calc-alkaline) and shoshonitic series rocks; (2) an Upper Miocene to Pleistocene (6·3–0·65 Ma), Si-poor, Na-rich group including basanites and alkali basalts to hawaiites and tephrites. Mafic samples from the Si–K-rich group generally show geochemical affinities with volcanic rocks from active subduction zones (e.g. Izu–Bonin and Aeolian island arcs), whereas mafic samples from the Si-poor, Na-rich group are geochemically similar to lavas found in intraplate volcanic settings derived from sub-lithospheric mantle sources (e.g. Canary Islands). The transition from Si-rich (subduction-related) to Si-poor (intraplate-type) magmatism between 6·3 Ma (first alkali basalt) and 4·8 Ma (latest shoshonite) can be observed both on a regional scale and in individual volcanic systems. Si–K-rich and Si-poor igneous rocks from the continental margins of southern Iberia and northwestern Africa are, respectively, proposed to have been derived from metasomatized subcontinental lithosphere and sub-lithospheric mantle that was contaminated with plume material. A three-dimensional geodynamic model for the westernmost Mediterranean is presented in which subduction of oceanic lithosphere is inferred to have caused continental-edge delamination of subcontinental lithosphere associated with upwelling of plume-contaminated sub-lithospheric mantle and lithospheric uplift. This process may operate worldwide in areas where subduction-related and intraplate-type magmatism are spatially and temporally associated

Sr/Ca and δ¹⁸O in a fast-growing Diploria strigosa coral - evaluation of a new climate archive for the tropical Atlantic

This study provides the first monthly resolved, 41-year record of geochemical variations (δ18O and Sr/Ca) in a fast-growing Diploria strigosa brain coral from Guadeloupe, Caribbean Sea. Linear regression yields a significant correlation of coral Sr/Ca (δ18O) with instrumental sea surface temperature (SST) on both monthly and mean annual scales (e.g., r = −0.59 for correlation between Simple Ocean Data Assimilation (SODA) SST and Sr/Ca, and r = −0.66 for δ18O; mean annual scale, p < 0.0001). The generated coral Sr/Ca (δ18O)-SST calibration equations are consistent with each other and with published equations using other coral species from different regions. Moreover, a high correlation of coral Sr/Ca and δ18O with local air temperature on a mean annual scale (r = −0.78 for Sr/Ca; r = −0.73 for δ18O; p < 0.0001) demonstrates the applicability of geochemical proxies measured from Diploria strigosa corals as reliable recorders for interannual temperature variability. Both coral proxies are highly correlated with annual and seasonal mean time series of major SST indices in the northern tropical Atlantic (e.g., r = −0.71 for correlation between the index of North Tropical Atlantic SST anomaly and Sr/Ca, and r = −0.70 for δ18O; mean annual scale, p < 0.001). Furthermore, the coral proxies capture the impact of the El Niño–Southern Oscillation on the northern tropical Atlantic during boreal spring. Thus fast-growing Diploria strigosa corals are a promising new archive for the Atlantic Ocean