We show that in school systems with grade retention or redshirting birth cohort size is negatively related to the grade-level share of students who are too old for their grade. This compositional effect gives…
Urban Air Mobility (UAM) beschreibt den kommerziellen Personentransport in der Luft, in oder zwischen Städten und ländlichen Gebieten, mittels eVTOL-Vehikeln (electric vertical take-off and landing vehicles).…
