Fluid physics, thermodynamics, and heat transfer experiments in space

An overstudy committee was formed to study and recommend fundamental experiments in fluid physics, thermodynamics, and heat transfer for experimentation in orbit, using the space shuttle system and a space laboratory. The space environment, particularly the low-gravity condition, is an indispensable requirement for all the recommended experiments. The experiments fell broadly into five groups: critical-point thermophysical phenomena, fluid surface dynamics and capillarity, convection at reduced gravity, non-heated multiphase mixtures, and multiphase heat transfer. The Committee attempted to assess the effects of g-jitter and other perturbations of the gravitational field on the conduct of the experiments. A series of ground-based experiments are recommended to define some of the phenomena and to develop reliable instrumentation

Compulsory Military Service in Germany Revisited

This paper estimates the causal impact of compulsory military service on men in Germany using social security and pension administrative data for the cohort of individuals born in the period 1932-1942. Due to the combination of laws restricting conscription only to men born on or after July 1, 1937, difference-in-differences estimates of the effect of conscription on average daily wages can be computed using cohorts of women as a comparison group. The results indicate that conscription had no significant impact on a draftee's labor-market performance, validating an earlier result using an alternative identification strategy.Dieses Papier zeigt den kausalen Einfluss der Wehrpflicht auf Männer in Deutschland. Es werden Daten der Sozialversicherung und administrativen Pensionsdaten für die Kohorte der Individuen, die im Zeitraum von 1932 bis 1942 geboren wurden, verwendet. Aufgrund der Kombination der Gesetze zur eingeschränkten Wehrpflicht kann nur bei Männern, die am 01. Juli 1937 oder danach geboren wurden mittels des Differenz von Differenzen-Ansatzes der Effekt der Wehrpflicht auf den durchschnittlichen Tageslohn geschätzt werden. Als Vergleichsgruppe wird die Kohorte der Frauen verwendet. Die Ergebnisse zeigen, dass die Wehrpflicht keinen signifikanten Einfluss auf die Arbeitsmarktentwicklung Wehrpflichtiger hat, was ein früheres Ergebnis mit einer alternativen Identifikationsstrategie bestätigt

Conceptual Analysis of Electron Transpiration Cooling for the Leading Edges of Hypersonic Vehicles

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140441/1/6.2014-2674.pd

A Dynamic Model of Unemployment with Migration and Delayed Policy Intervention

The purpose of this paper is to build and analyse a model of unemployment, where jobs search is open to both natives and migrant workers. Markets and government intervention respond jointly to unemployment when creating new jobs. Full employment of resources is the focal point of policy action, stimulating vacancy creation. We acknowledge that policy is implemented with delays, and capture labour market outcomes by building a non-linear dynamic system. We observe jobs separation and matching, and extend our model to an open economy with migration and delayed policy intervention meant to reduce unemployment. We analyse the stability behaviour of the resulting equilibrium for our dynamic system, including models with Dirac and weak kernels. We simulate our model with alternative scenarios, where policy action towards jobs creation considers both migration and unemployment, or just unemployment

No Excuses Charter Schools: A Meta-Analysis of the Experimental Evidence on Student Achievement

While charter schools differ widely in philosophy and pedagogical views, the United States’s most famous urban charter schools typically use the No Excuses approach. Enrolling mainly poor and minority students, these schools feature high academic standards, strict disciplinary codes, extended instructional time, and targeted supports for low-performing students. The strenuous and regimented style is controversial amongst some scholars, but others contend that the No Excuses approach is needed to rapidly close the achievement gap. We conduct the first meta-analysis of the achievement impacts of No Excuses charter schools. Focusing on experimental studies, we find that No Excuses charter schools significantly improve math scores and reading scores. We estimate gains of 0.25 and 0.16 standard deviations on math and literacy achievement, respectively, as the effect of attending a No Excuses charter school for one year. Though the effect is large and meaningful, we offer some caveats to this finding and discuss policy implications for the United States as well as other countries

Individual Heterogeneity in the Returns to Schooling: Instrumental Variables Quantile Regression Using Twins Data

Considerable effort has been exercised in estimating mean returns to education while carefully considering biases arising from unmeasured ability and measurement error. Recent work has investigated whether there are variations from the “mean” return to education across the population with mixed results. We use an instrumental variables estimator for quantile regression on a sample of twins to estimate an entire family of returns to education at different quantiles of the conditional distribution of wages while addressing simultaneity and measurement error biases. We test whether there is individual heterogeneity in returns to education and find that: more able individuals obtain more schooling and that higher ability individuals (those further to the right in the conditional distribution of wages) have higher returns to schooling consistent with a non-trivial interaction between schooling and unobserved abilities in the generation of earnings. The estimated returns are never lower than 9 percent and can be as high as 13 percent at the top of the conditional distribution of wages but they vary significantly only along the lower to middle quantiles. Our findings may have meaningful implications for the design of educational policies

The Eurotower Strikes Back

The 2008 global financial crisis came with fears—and, for some, hopes—that a new wave of public mobilization would emerge in industrialized countries. Especially throughout the European Union (EU), the epicenter of the crisis, large protests were expected. Yet, the energy with which social groups mobilized against the proposed austerity measures quickly fizzled. This article provides new evidence for why this was the case. In line with Neo-Keynesian theory, we argue that the interest rate adjustments and political announcements of the European Central Bank (ECB) limited the potential for mass unrest in the member states of the Economic and Monetary Union (EMU) affected by the crisis. We provide evidence for our argument with yearly panel data and a new original data set of monthly political protests between 2001 and 2013. Our analyses support the hypothesis that the ECB was able to successfully assuage dissatisfaction with the limited reform options of the Eurozone member states in the wake of the Eurocrisis

Evaluating the Impacts of Subsidies on Innovation Activities in Germany

Innovations are a key factor to ensure the competitiveness of establishments as well as to enhance the growth and wealth of nations. But more than any other economic activity, decisions about innovations are plagued by failures of the market mechanism. As a response, public instruments have been implemented to stimulate private innovation activities. The effectiveness of these measures, however, is ambiguous and calls for an empirical evaluation. In this paper we make use of the IAB Establishment Panel and apply various microeconometric methods to estimate the effect of public measures on innovation activities of German establishments. We find that neglecting sample selection due to observable as well as to unobservable characteristics leads to an overestimation of the treatment effect and that there are considerable differences with regard to size class and betweenWest and East German establishments