Events

The predictive power of the variance risk premium (VRP) for realized volatility depends critically on aligning the maturity of the option-implied variance measure with the forecast horizon. We exploit the CBOE's progressive expansion of the SPY option expiration calendar — from weekly Friday expirations through Wednesday and Monday additions to daily expirations in 2022 — as a natural experiment. Using SPY options from 2013 to 2025, we construct two VRP measures: one restricted to Friday-expiring weekly options (replicating the pre-expansion constraint) and one using the best-available expiration. Within a nested HAR framework evaluated across one-, five-, and ten-day horizons, we find that VRP inclusion reduces out-of-sample mean squared prediction error by 12–18%, with additional significant gains from maturity alignment concentrated at short horizons and in the post-2022 daily-expiry regime. Statistical improvements are corroborated by realized utility gains. Our findings establish a direct link between exchange design decisions and forecast quality.

This research explores how mobility big data can be used to understand urban travel behavior and evaluate policy implications. The data sources include public transport smart cards, public bike systems, and mobile phone data. In particular, the transport card–based analysis demonstrates the benefits of Seoul’s integrated fare system with free transfers. The presentation will also briefly introduce data from autonomous delivery robots deployed in Seoul as a potential emerging urban data source.

Optimism—the expectation that future events will be better than they actually are—is a widely spread cognitive bias. How can this bias survive? Previous studies have mostly claimed that it survives because it benefits the optimist. However, I show that optimism may have evolved not to benefit the optimist but her family or community, who share her genes. I present an agent-based simulation model in which optimism serves as a proactive/pro-exploratory bias, leading the optimist to explore more opportunities than an unbiased individual. This may harm the optimist herself, but it benefits her relatives who can learn from, imitate, or benefit from her explorations in other ways. In this way, kin selection can explain the origin and persistence of optimism.

Germany was the first country worldwide to introduce a structured reimbursement pathway for digital therapeutics (DiGA), effectively allowing physicians to prescribe smartphone apps covered by statutory health insurance. In this seminar, Simon Reif presents recent research evaluating whether this pioneering regulation successfully incentivized innovation in the digital health market.  Using high-frequency data from the Apple App Store and synthetic control methods, the study analyzes the market entry of health apps following the policy's introduction. The findings reveal a significant increase in the number of German-language digital therapeutics; however, this quantity did not translate into a broader diversity of medical conditions treated. Furthermore, the surge was largely driven by apps that monetize patient data for advertising rather than high-quality applications backed by scientific evidence. The presentation will discuss the implications of these results for designing policy that balances market incentives with patient privacy and care quality.

Teaser: Simon will be holding a separate, short workshop on the reproducible research tools used at his institute. Join us to learn how to implement these transparent workflows in your own analysis. 

Motherhood is associated with persistent penalties in both labour market outcomes and health. However, the role of family policies in mitigating these effects, particularly with respect to maternal mental health, remains unclear. This paper examines the impact of extending paternity leave on maternal mental health. Using administrative health records covering all publicly funded births in Catalonia (Spain) between 2006 and 2024, we implement a local difference-in-differences design around the April 1st, 2019 reform, which introduced partially mandatory paternity leave for fathers. The analysis focuses on first time mothers giving birth within a three-month window around the reform cutoff and compares them to a control cohort from 2016. Maternal mental health is measured using diagnoses and prescription records for stress-related, mood-related, and broader mental health conditions drawn from primary care and pharmacy data. We find an increase in stress-related diagnoses and in the use of antidepressants and anxiolytics from the second year after childbirth among mothers exposed to the reform. These effects are concentrated among older mothers (above the median age of 31) and among those who do not have a second child within four years after birth. We find suggestive evidence that these patterns may be related to increased healthcare use and to stress-related mechanisms, including delayed fertility, changes in labour market attachment, and relationship instability. Ongoing work will extend the analysis to additional mental health outcomes and to subsequent paternity leave reforms

In 2025, a survey of 8,000 students and employees at ten Czech universities analysed commuting behaviour using a logit model of mode choice. Public transport dominated (47%), followed by car (32%) and walking or cycling (21%), with higher car use among employees and higher-income respondents. Distance, age (non-linear effect), and children significantly increased the likelihood of car use, particularly beyond 10 km. Differences across universities reflected urban size and topography, with higher public transport shares in large agglomerations. Key barriers to sustainable mobility were habits, distance, and public transport quality, while faster connections, lower costs, improved cycling infrastructure, and limited parking were identified as main drivers of modal shift.

What happens when firms merge, and how do economists determine whether competition is harmed? This lecture offers an accessible introduction to merger analysis, combining theory with a real-world case study. It explores how economists define markets, measure competitive pressure, and assess the likely impact of mergers on consumers. The session also highlights how data-driven tools and empirical methods are increasingly central to competition policy.