The Effect of Household Appliances on Female Labor Force Participation: Evidence from Micro Data

In this paper we estimate the effect of household appliance ownership on the labor force participation rate of married women using micro-level data from the 1960 and 1970 U.S. Censuses. In order to identify the causal effect of home appliance ownership on married women's labor force participation rates, our empirical strategy exploits both time-series and cross-sectional variation in these two variables. To control for endogeneity, we instrument a married woman's ownership of an appliance by the average ownership rate for that appliance among single women living in the same U.S. state. Single women's labor force participation rates did not increase between 1960 and 1970. We find that the diffusion of home appliances accounts for about one-third of the observed increase in married women's labor force participation rates during the 1960's.

Smaller family sizes and ageing populations may reduce long-run savings rates

As developing countries embark on demographic transitions, the phenomenon of declining birth rates and family size becomes an increasingly important policy dilemma. Demography has implications for a country’s labour supply, savings rates, and capital formation, all of which shape and influence its economic growth. In today’s blog, the authors argue that increases in aggregate savings from declining family sizes may be transitory, and as populations begin ageing, a declining ratio of working-aged to retired workers may reduce long-run savings rates

Alpine Pumping

„Alpines Pumpen“ ist ein regionales Zirkulationsphänomen, das sich tagsüber zwischen Gebirge und Vorland bei hoher Sonneneinstrahlung und schwachen Druckgradienten ausbildet. Die Luft im Alpenraum erwärmt sich tagsüber rascher als im Vorland, es bildet sich ein Hitzetief und die bodennahe Luft wird konvektiv nach oben verfrachtet.Aus dem Alpenvorland strömt Luft in einer Einströmschicht zu den Alpen und ersetzt die dort konvektiv gehobene Luft. Luftbeimengungen in der Einströmschicht gelangen so vom Alpenvorland in die freie Troposphäre bis über die Alpengipfel. Semivolatile Luftbeimengungen rekondensieren bei den niedrigen Temperaturen in den Hochalpen und reichern sich dort an. Für dieses häufige Transportphänomens, das durch intensiveren Vertikalaustausch über dem Hochgebirge ausgelöst wird, wurde die Bezeichnung „Alpines Pumpen“ gewählt. Es wird in diesem Beitrag näher beschrieben

Determination of recombination coefficients in InGaN quantum-well light-emitting diodes by small-signal time-resolved photoluminescence

We suggest a novel technique for the evaluation of the recombination coefficients corresponding to Shockley–Read–Hall, radiative, and Auger recombination that occur in InGaN/GaN-based light-emitting diodes (LEDs). This technique combines the measurement of the LED efficiency as a function of LED drive current with a small-signal time-resolved photoluminescence measurement of the differential carrier life time (DLT). Using the relationships between the efficiency and DLT following from the empirical ABC-model, one can evaluate all three recombination coefficients. The suggested technique is applied to a number of single- and multiple-quantum well LEDs to gain a deeper insight into the mechanisms ultimately limiting their efficiency

Temperature-dependent recombination coefficients in InGaN light-emitting diodes : hole localization, Auger processes, and the green gap

We obtain temperature-dependent recombination coefficients by measuring the quantum efficiency and differential carrier lifetimes in the state-of-the-art InGaN light-emitting diodes. This allows us to gain insight into the physical processes limiting the quantum efficiency of such devices. In the green spectral range, the efficiency deteriorates, which we assign to a combination of diminishing electronhole wave function overlap and enhanced Auger processes, while a significant reduction in material quality with increased In content can be precluded. Here, we analyze and quantify the entire balance of all loss mechanisms and highlight the particular role of hole localization

Micro-Data Evidence on Family Size and Chinese Household Saving Rates

This paper examines the impact of family size on household saving. We first study a theoretical life-cycle model that includes finite lifetimes and saving for retirement and in which parents care about the consumption by their dependent children. The model implies a negative relationship between the number of dependent children in the family and the household saving rate. Then, we test the model\u27s implications using new survey data on household finances in China. We use the differential enforcement of the one-child policy across counties to address the possible endogeneity between household saving and fertility decisions in a two-stage least squares Tobit regression. We find that Chinese families with fewer dependent children have significantly higher saving rates. The data yields several additional insights on household saving patterns. Households with college-age children have lower saving rates, and households residing in urban areas have higher saving rates and a lower ratio of education expenditures to income. However, having an additional child reduces saving rates more for households in urban areas than in rural areas. Our regressions also indicate that saving rates vary with age and tend to be higher for households with more workers, higher education, better health, and more assets

Chinese household saving and dependent children: Theory and evidence

This paper examines the impact of family size on household saving. We first study a theoretical life-cycle model that includes finite lifetimes and saving for retirement and in which parents care about the consumption by their dependent children. The model implies a negative relationship between the number of dependent children in the family and the household saving rate. Then, we test the model\u27s implications using new survey data on household finances in China. We use the differential enforcement of the one-child policy across counties to address the possible endogeneity between household saving and fertility decisions in a two-stage least squares Tobit regression. We find that Chinese families with fewer dependent children have significantly higher saving rates. The data yields several additional insights on household saving patterns. Households with college-age children have lower saving rates, and households residing in urban areas have higher saving rates and a lower ratio of education expenditures to income. However, having an additional child reduces saving rates more for households in urban areas than in rural areas. Our regressions also indicate that saving rates vary with age and tend to be higher for households with more workers, higher education, better health, and more assets

Differences of movement pattern between Asiatic wild ass (Equus hemionus) and Przewalski’s horse (Equus ferus przewalskii)

Das Analysieren von Bewegungsmustern verschiedener Tiere gibt Aufschlüsse darüber, wie Tiere mit ihrer Umwelt interagieren. Aufgrund Artunterschiede, Umweltheterogenität, unterschiedlicher Ressourcenauswahl und physikalische Eigenschaften zeigen Tiere verschiedene Bewegungsstrategien. Ich wertete GPS-Daten, gesammelt im Zeitraum von 2001 bis 2007 in der Mongolei, von drei Asiatischen Wildeseln und sechs Przewalski-Pferden aus. Unter Verwendung der Variablen "zurückgelegte Strecke" und "Abweichwinkel" analysierte ich individuelle Datensätze um mögliche Tendenzen von Bewegungsstrategien hinsichtlich Artenunterschieds (Przewalski- Pferd versus Asiatischer Wildesel), Gebietsunterschieds (Wildesel im SW der Gobi versus Wildesel im SE der Gobi) und Management (etablierte versus kürzlich ausgesetzte Przewalski-Pferde) festzustellen. Aufgrund des geringen Stichprobenumfangs der verschiedenen Individuen legte ich meinen Schwerpunkt auf eine erste qualitative Einschätzung der Bewegungsstrategien als Grundlage für weitere Hypothesen. Art: Das Revier, in dem sich die Asiatischen Wildesel aufhielten, war mit durchschnittlich 22624 km² deutlich größer als jenes der Przewalski-Pferde, das nur durchschnittlich 510 km² betrug. Im Gegensatz zu den Przewalski-Pferden zeigten die Wildesel eine nahezu lineare Beziehung zwischen zurückgelegter Distanz und Zeitintervall. Dies deutet auf eine hohe Mobilität seitens der Wildesel. Die Esel legten mit 8451 m höhere Tagesstrecken als die Pferde mit 3177 m zurück. Die Asiatischen Wildesel bewegten sich in größeren Abweichwinkeln als die Wildpferde. Die Pferde tendierten eher zu Residenz; sie bevorzugten Bewegungen mit Abweichwinkeln von weniger als 90°. Die Wildesel zeigten keine höhere Autokorrelation der Distanzen und Abweichwinkel. Weiters war die Korrelation zwischen Tagesdistanzen und Winkel bei den Eseln nicht stärker ausgeprägt als bei den Pferden. 4 Gebiet: Innerhalb der Gruppe der Wildesel legten die Esel im Südosten der Gobi (Bereich: 9646 m – 7606 m) keine signifikant längeren Tagesstrecken zurück als der Esel in der Great Gobi B (8102 m). Weiters konnten keine merklichen Unterschiede im Abweichwinkel zwischen den Tieren im Südosten (Mittelwert: 90,22°) und dem Esel im Südwesten (88,6°) festgestellt werden. Die Esel im SO wiesen eine höhere Autokorrelation der Tagesdistanzen und Abweichwinkel auf als der Esel im SW. Auch konnte bei den Eseln im südöstlichen Teil der Gobi ein stärkerer Zusammenhang zwischen Tagesdistanz und Abweichwinkel ermittelt werden. Management: Innerhalb der Wildpferde besiedelten die bereits etablierten Pferde mit durchschnittlich 428 km² keine signifikant größeren Flächen als die erst kürzlich entlassenen Tiere mit durchschnittlich 591 km². Die etablierten Pferde zeigten jedoch größere Tagesdistanzen und Abweichwinkel als die unlängst ausgesetzten Tiere. Keine auffallenden Unterschiede gab es allerdings bei der Autokorrelation von Tagesdistanz und Abweichwinkel und bei der Korrelation zwischen Distanz und Abweichwinkel.Analysing animal movement reveals how animals interact with their environment and is necessary to understand their foraging behaviour. Due to landscape heterogeneity, species differences, various resource selection and physical features animals show various movement tactics. I analysed the GPS data of 6 Przewalski’s horses and 3 Asiatic wild asses collected in the Mongolian Gobi from 2001 to 2007. Using the variables travel distance and turning angle I analysed individual datasets to look for possible species-specific (wild asses versus P-horses), area-specific (wild asses in the SE Gobi versus the SW Gobi) and management specific (established versus newly released P-horse groups) trends in movement strategies. Due to the small sample size of different individuals my focus was on a first qualitative assessment of movement strategies as a basis for future hypothesis testing. Species: Asiatic wild asses had home ranges from 4784 km² to 42776 km². Contrary to the Przewalski’s horses, the Asiatic wild asses showed an almost linear relationship between the travel distance and the time interval between successive locations suggesting a high mobility. Mean daily distance travelled averaged 8451 m. The wild asses moved in larger turning angles than Przewalski’s horses. Przewalski’s horses covered home ranges from 290 km² to 1357 km² and located near watering places. Mean daily distance covered averaged 3177 m. The horses tended to be more resident because they preferred moving in turning angles less than 90°. The autocorrelation of travel distances and turning angles and the correlation between these parameters were not significantly stronger for wild asses than for wild horses. Area: No significant differences in travel distances were found between the 2 wild asses in the SE Gobi (range: 9646 m – 7606 m) and the wild ass in the Great Gobi B (8102 m) and also no noticeable differences in turning angles were detected between the animals in the SE (mean: 90,22°) and the ass in the SW (88,6°). The autocorrelation of daily travel distances and daily turning angles were stronger for the asses in the SE than for the ass in the SW. The Asiatic wild asses in the SE Gobi exhibited a stronger correlation between travel distance and turning angle than the wild ass in the Great Gobi B. Management: Of the Przewalski’s horses, the established horses (mean: 428 km²) did not show significant larger home ranges than the newly released horses (mean: 591 km²). However, between the two groups there were statistical differences in daily travel distances, 3 but not so in daily turning angle. Established wild horses did not revealed a stronger autocorrelation of daily travel distances and daily turning angles and a stronger correlation between distance and angle than the newly released wild horses