SoSe 2021
Abstracts SoSe 2021
Studentischer Alltag in Pandemiezeiten: Eine Tagebuchstudie
an der Martin-Luther-Universität Halle-Wittenberg (Hoßbach,
Bachmann, Roth)
Die Corona Pandemie hat den Alltag von Studierenden tiefgreifend verändert und insbesondere Studienanfänger*innen vor große Herausforderungen gestellt. Um den studentischen Alltag in der Pandemie besser zu verstehen, haben wir Studierende der MLU in der Zeit des Lockdowns Anfang 2021 über 3 Wochen hinweg mit einem app-basierten Reflexionstagebuch begleitet. Eine Interventionsgruppe erhielt in diesem Zeitraum ein Coaching zur proaktiven Gestaltung Ihres Studienalltags auf Basis Ihrer Reflexionsdaten. Die vorläufigen Ergebnisse zeigen eine Stärkung der Selbstführungskompetenz, kreativen Selbstwirksamkeitserwartung und Resilienz von Studierenden der Interventions- gegenüber der Kontrollgruppe. Wir geben Einblicke in das alltägliche Verhalten und Empfinden von Studierenden vor dem Hintergrund der Pandemie und diskutieren deren Implikationen für die Ausgestaltung zukünftiger Unterstützungsangebote für Studierende.
Wheat futures price volatility and Russian export restrictions (Heigermoser)
Russia, the world’s largest wheat exporter since 2017/18, has repeatedly restricted its grain exports with taxes, quotas or bans. Such policy intervention can induce uncertainty to futures, as well as spot markets, jeopardizing global food security. Building on high-frequency, transaction-specific wheat futures price data from the Chicago Board of Trade (July 2013 through October 2020), we measure contemporaneous, pre- and post-announcement volatility effects of Russian grain trade policy announcements. Computing various realized volatility measures from five-minute intra-day returns, our results suggest increased volatility on days leading up to newswire reports on Russian grain export policy. For comparison, we find similar pre-announcement effects on days preceding pre-scheduled crop reports released by the US Department of Agriculture, corresponding to publications of analyst poll results. We confirm that realized volatility measures are well-equipped to analyze punctual volatility events compared to conditional GARCH volatility, which can only depict longer-lasting volatility effects.
Keywords: Trade restrictions, futures markets, realized volatility, high frequency, Russia
Multi-objective location problems with variable
domination structure. (B. Zargini)
We introduce an inverse variational inequality to investigate the solutions of a multi-objective optimization problem with respect to variable domination structure. In particular, mild conditions are established to study the relationships between nondominated solutions and the solutions of the inverse variational inequality. Applying these results, we study a mathematical model for location problems in the case that different preferences with respect to different facilities are at hand. Finally, we adjust a new version of PROMETHEE method to obtain solutions for a scaralized multi-objective location problem.
Keywords: Multi-objective programming problem, Variable domination structure, Location problem, Weight function, PROMETHEE method
Choice architecture and incentives increase COVID-19 vaccine intentions
and test demand. (Szech)
Willingness to vaccinate and test are critical in the COVID-19 pandemic. We study the effects of two measures to increase vaccination and testing: “choice architecture” and monetary compensations. Choice architecture has the goal of “nudging” people into a socially desired direction without affecting their choice options. Compensations reward vaccine takers and are already in use by some organizations. Yet there is the concern that compensations may decrease vaccination if compensations erode intrinsic motivation to vaccinate. We show that both approaches, compensations and choice architecture, significantly increase COVID-19 test and vaccine demand. Yet, for vaccines, low compensations can backfire.