Program

In a network formation problem, pairwise stability is a cornerstone concept like Nash Equilibria in game theory. In fact, previous literature has demonstrated that under certain conditions pairwise stable networks are guaranteed to exist and that they have an intrinsic connection to Nash Equilibria when links are unweighted. This relationship allows for the implementation of algorithmic procedures to find pairwise stable networks. Recently, the existence result was generalized to unweighted networks (i.e., links take values in the real numbers), but computational approaches applicable to this setting remain unexamined in the literature. This thesis bridges this gap by developing a stochastic and a tracing algorithm where pairwise stability is achieve through the identification of a Nash equilibrium in a noncooperative game involving nodes and links. The algorithms are then applied to a couple pertinent applications from the literature.

This presentation explores the design and evaluation of Approval-Based Committee (ABC) rules from a social welfare perspective. As multi-winner elections gain importance in both theoretical research and practical applications, balancing collective satisfaction with equitable representation becomes crucial. I analyze key ABC rules—including Approval Voting, Proportional Approval Voting, Chamberlin–Courant, and Monroe rules—highlighting their differing welfare outcomes and computational trade-offs. In addition to welfare maximization, I also examine fairness-oriented criteria such as Proportional Justified Representation (PJR) and Extended Justified Representation (EJR), and the tensions that arise when these fairness goals conflict with utilitarian objectives. The talk also reviews optimization techniques such as exact algorithms, approximation methods, and heuristics aimed at improving welfare performance. Finally, I outline several possible directions for future improvement, focusing on how voting rules might better integrate welfare objectives with fairness considerations in real-world settings.

The purpose of this thesis is twofold. First, we estimate macroeconomic effects of monetary policy by Proxy Structural Vector Autoregressions (SVAR). Second, we forecast the US gross domestic product (GDP) by mixed-frequency Bayesian Vector Autoregressions (BVAR) and their combination constructed by Bayesian Predictive Synthesis (BPS). We contribute to macroeconometric literature in two respects. First, we orthogonalize the monetary policy surprises (MPS) with a broader set of sentiments: Beige Books, Federal Reserve System (Fed) speeches, Fed testimonies. Second, we include sentiment scores from the Federal Open Market Committee (FOMC) internal meetings as instrumental variables in the Proxy SVAR. In  comparison to quarterly BVAR we find a higher forecast performance of mixed- frequency BVARs and their combination from the current-quarter to 4-quarter-ahead  horizon: (i) 14.98-38.62% by blocking BVAR, (ii) 26.68-40.31% by Cube root BVAR, (iii) 11.01-38.33% by Latent BVAR, (iv) 25.68-47.08% by BPS. With orthogonalized MPS we observe a lower response of consumer price index and industrial production compared to a Proxy SVAR without orthogonalization of MPS. Impulse response functions (IRFs) are robust to sentiment scores from FOMC internal meetings that are included as additional instrumental variables in the Proxy SVAR.

Financial market participation helps households to secure and control their future financial situation. This study empirically tested whether financial market participation improves household well-being, using Dutch DNB micro-household survey panel data from five survey waves (2020-2024). Fixed-effects and between-effects panel regression models are adopted to distinguish within-individual and across-individual variations over time. Results indicate a modest, statistically significant negative relationship between financial market participation and happiness, which serves as a proxy for subjective well-being. This relationship was found robust to alternative measures, such as assets from investments and their share in the asset portfolio. Findings suggest financial market participation does not enhance subjective well-being and, in the context of the Dutch population, may be associated with a slight decline in reported overall happiness. Employment status, owning real estate, higher health conditions, marriage status and perceived financial household status show significant and high positive effects on happiness.