Behavioral Interventions and Students' Success at University - Evidence from Randomized Field Experiments

In den letzten Jahrzehnten hat die Forschung die verschiedenartigen individuellen und sozialen Erträge der Hochschulbildung dokumentiert. Die Realisierung dieser Erträge wird jedoch in vielen Ländern durch hohe Abbruchquoten und lange Studiendauern beeinträchtigt. Bei der Untersuchung der Ursachen für fehlenden Studienerfolg verweist die neuere Literatur auf die entscheidende Rolle von sogenannten ``behavioral biases‘‘ und den daraus resultierenden Bedarf an Maßnahmen, die diese ausgleichen. Vor diesem Hintergrund untersucht diese Dissertation die Wirksamkeit mehrerer kostengünstiger und einfach durchzuführender Maßnahmen zur Steigerung des Studienerfolgs und leistet damit einen Beitrag zu der noch jungen, aber wachsenden Forschung über verhaltensökonomisch motivierte Interventionen im Hochschulbereich. Unter Verwendung von randomisierten Feldexperimenten zur kausalen Evaluation untersuchen die vier zentralen Kapitel dieser Dissertation, i) ob soziale Informationen über das frühere Verhalten anderer die Teilnahme an einem Mathe Vorkurs erhöhen können und ob eine erhöhte Kursteilnahme zu besseren akademischen Leistungen im ersten Studienjahr führt (Kapitel 2), ii) ob relatives Leistungsfeedback bezüglich der akkumulierten Leistungspunkte den kurz- und langfristigen akademischen Erfolg erhöhen kann (Kapitel 3 und 4), und iii) ob eine unverbindliche Selbstverpflichtung, gemäß der empfohlenen Studienstruktur zu studieren, und Erinnerungsschreiben in der Lage sind, den Studienerfolg von Studierenden zu fördern (Kapitel 5). Insgesamt liefert diese Dissertation ein breites Spektrum an Belegen für die Vielseitigkeit und das Potenzial verhaltensökonomischer Maßnahmen. Sie können die akademischen Leistungen direkt oder indirekt verbessern, entscheidungsrelevante Informationen liefern, die den Studierenden häufig nicht zur Verfügung stehen, oder sie können spezifischen Abweichungen vom rationalen Verhaltensmodell -- wie Prokrastination und eingeschränkte Aufmerksamkeit -- entgegenwirken. Hervorzuheben ist, dass die Kapitel 4 und 5 einige der ersten Belege dafür liefern, dass verhaltensökonomisch motivierte Maßnahmen auch langfristig erhebliche positive Auswirkungen auf den Studienerfolg haben können. Die Kapitel der Dissertation zeichnen jedoch auch ein differenziertes Bild und zeigen, dass Effekte häufig heterogen sind. In vielen Situationen kann daher eine zielgerichtete Umsetzung der vorgeschlagenen Maßnahmen erforderlich sein, um ungewollte Auswirkungen zu verhindern. Gleichzeitig werden aber auch Beispiele gegeben, wie ökonometrische Methoden eingesetzt werden können, um die Nutznießer einer Intervention genauer zu identifizieren.Research over the past decades has documented the various individual and social returns to tertiary education. In many countries, however, the realization of those returns is jeopardized by high dropout rates and delayed graduation. Investigating the underlying reasons for the lack of academic success, the recent literature points to the critical role of behavioral biases and the resulting need for interventions that address them. Against this background, this thesis investigates the effectiveness of several low-cost and easy-to-implement measures that aim to increase students’ success at university, thereby contributing to the young but growing body of research on behaviorally informed interventions in higher education. Using randomized field experiments for causal evaluation, the four main chapters of this thesis study i) whether social information about the past behavior of others can raise remedial math course participation and if increased course attendance translates into higher academic performance in the first year of studies (Chapter 2), ii) whether relative performance feedback on accumulated course credits can increase short- and long-term academic achievement (Chapters 3 and 4), and iii) whether a non-binding commitment to study according to the recommended study structure and reminder letters are able to help students succeed in university (Chapter 5). Taken together, this thesis provides a broad range of evidence for the versatility and potential of behaviorally informed measures. They can improve academic performance directly or indirectly, provide decision-relevant information that is frequently not available to students, or be used to address specific biases -- such as procrastination and limited attention. Crucially, Chapters 4 and 5 provide some of the first evidence that behavioral interventions can have substantial positive effects on long-term academic success. Yet, the chapters of this thesis also paint a nuanced picture and show that effects are often heterogeneous. In many situations, a targeted implementation of the proposed measures may therefore be necessary to prevent unwanted effects. At the same time, examples of how econometric methods can be used to identify the beneficiaries of an intervention more precisely are provided.2022-01-2

Relative Performance Feedback and the Effects of Being Above Average - Field Experiment and Replication

In a randomized field experiment, we give first-year students in higher education feedback on their relative performance and show that the type of feedback matters, as feedback increases performance only if it informs the student that they placed above average in the past. We reproduce the results in a replication experiment and investigate mechanisms: The effects are not driven by above-average students reacting particularly well to feedback due to individual characteristics; rather, the information about being above average makes feedback effective. We present evidence that individuals focus on good news to adjust their beliefs, and that feedback can offset disadvantages faced by individuals who are held back by their own underestimation of relative abilities. Once beliefs between controls and the treated converge, repeated treatment does not add to the effects

Normatively Framed Relative Performance Feedback – Field Experiment and Replication

Feedback can help individuals put their performance into perspective, especially when transitioning into a new environment such as university or a different job. In a randomized field experiment we give first-year university students normatively framed relative performance feedback about their accumulated course credits. We find an increase in subsequent performance, but only when the feedback is positive. Using a regression discontinuity design, we show that the improved performance is not driven by unobserved characteristics of those receiving positive feedback, but that it is indeed due to the positive rather than negative nature of the feedback. We administer a replication experiment with the next wave of first-year students one year later and reproduce the results. Survey data provides suggestive evidence that positive feedback has an effect on behavior when students underestimate their relative performance, and that consistent with a mechanism of selective information processing, individuals focus on positive feedback to adjust their beliefs

Normatively Framed Relative Performance Feedback – Field Experiment and Replication

Feedback can help individuals put their performance into perspective, especially when transitioning into a new environment such as university or a different job. In a randomized field experiment we give first-year university students normatively framed relative performance feedback about their accumulated course credits. We find an increase in subsequent performance, but only when the feedback is positive. Using a regression discontinuity design, we show that the improved performance is not driven by unobserved characteristics of those receiving positive feedback, but that it is indeed due to the positive rather than negative nature of the feedback. We administer a replication experiment with the next wave of first-year students one year later and reproduce the results. Survey data provides suggestive evidence that positive feedback has an effect on behavior when students underestimate their relative performance, and that consistent with a mechanism of selective information processing, individuals focus on positive feedback to adjust their beliefs

Pantropical variability in tree crown allometry

Aim Tree crowns determine light interception, carbon and water exchange. Thus, understanding the factors causing tree crown allometry to vary at the tree and stand level matters greatly for the development of future vegetation modelling and for the calibration of remote sensing products. Nevertheless, we know little about large‐scale variation and determinants in tropical tree crown allometry. In this study, we explored the continental variation in scaling exponents of site‐specific crown allometry and assessed their relationships with environmental and stand‐level variables in the tropics. Location Global tropics. Time period Early 21st century. Major taxa studied Woody plants. Methods Using a dataset of 87,737 trees distributed among 245 forest and savanna sites across the tropics, we fitted site‐specific allometric relationships between crown dimensions (crown depth, diameter and volume) and stem diameter using power‐law models. Stand‐level and environmental drivers of crown allometric relationships were assessed at pantropical and continental scales. Results The scaling exponents of allometric relationships between stem diameter and crown dimensions were higher in savannas than in forests. We identified that continental crown models were better than pantropical crown models and that continental differences in crown allometric relationships were driven by both stand‐level (wood density) and environmental (precipitation, cation exchange capacity and soil texture) variables for both tropical biomes. For a given diameter, forest trees from Asia and savanna trees from Australia had smaller crown dimensions than trees in Africa and America, with crown volumes for some Asian forest trees being smaller than those of trees in African forests. Main conclusions Our results provide new insight into geographical variability, with large continental differences in tropical tree crown allometry that were driven by stand‐level and environmental variables. They have implications for the assessment of ecosystem function and for the monitoring of woody biomass by remote sensing techniques in the global tropics

Social Information and Educational Investment - Nudging Remedial Math Course Participation

Using randomized field experiments, I investigate the effectiveness of two social information interventions at increasing participation in a voluntary remedial math course for university students. In Intervention 1, incoming students receive invitation letters with information about the course sign-up rate in a previous semester. In Intervention 2, the students who signed up for the course receive reminder letters that include information on how helpful the course has been evaluated by previous students. On average, neither intervention increases participation in the course, but further analyses reveal that the effects of Intervention 1 are heterogeneous along two dimensions: First, by increasing the salience of the course, it raises attendance among students who enroll late in their study program, which in turn increases their first-year performance and closes the achievement gap to early enrollees. Second, the effect of the information about the past sign-up rate depends on the predicted ex-ante sign-up probability. Students for whom the prediction falls just short of the past sign-up rate increase sign-up and participation, while the opposite is true for students whose sign-up probability exceeds the social information. Along this dimension, however, the changes in attendance do not carry over to academic achievements