SC-block: Supervised contrastive blocking within entity resolution pipelines

Millions of websites use the schema.org vocabulary to annotate structured data describing products, local businesses, or events within their HTML pages. Integrating schema.org data from the Semantic Web poses distinct requirements to entity resolution methods: (1) the methods must scale to millions of entity descriptions and (2) the methods must be able to deal with the heterogeneity that results from a large number of data sources. In order to scale to numerous entity descriptions, entity resolution methods combine a blocker for candidate pair selection and a matcher for the fine-grained comparison of the pairs in the candidate set. This paper introduces SC-Block, a blocking method that uses supervised contrastive learning to cluster entity descriptions in an embedding space. The embedding enables SC-Block to generate small candidate sets even for use cases that involve a large number of unique tokens within entity descriptions. To measure the effectiveness of blocking methods for Semantic Web use cases, we present a new benchmark, WDC-Block. WDC-Block requires blocking product offers from 3,259 e-shops that use the schema.org vocabulary. The benchmark has a maximum Cartesian product of 200 billion pairs of offers and a vocabulary size of 7 million unique tokens. Our experiments using WDC-Block and other blocking benchmarks demonstrate that SC-Block produces candidate sets that are on average 50% smaller than the candidate sets generated by competing blocking methods. Entity resolution pipelines that combine SC-Block with state-of-the-art matchers finish 1.5 to 4 times faster than pipelines using other blockers, without any loss in F1 score

Ethnic friendship segregation in the school class – The role of homophily preferences of gender, socioeconomic status, and religion in four European countries

This dissertation explores social integration by studying the evolution of friendships between young migrants and natives in school classes across Germany, the Netherlands, the United Kingdom, and Sweden, utilizing data from the Children of Immigrants Longitudinal Survey in Four European Countries (CILS4EU). It aims to identify the social factors influencing the formation of inter-ethnic and inter-religious friendships, focusing on the boundaries between ethnic groups within school environments. The first study emphasizes the significance of opportunity structure in friendship formation between natives and migrants. Employing ego-level (pooled OLS) and dyad-level (2-step approach on firthlogit and multilevel logit) techniques, it demonstrates that gender availability within ethnic groups plays a crucial role in inter-ethnic friendship formation. Specifically, lower gender availability within one's own ethnic group correlates with an increased probability of cross-group friendships. This highlights the dominance of gender over ethnicity in shaping social segregation among youth in educational environments, underscoring a broader pattern: the pivotal role of opportunity structure “within” social categories. In the second study, grounded in exchange theory, the research explores the role of social exchange in intergroup friendships between native and migrant adolescents. Utilizing ego-level (OLS) and dyad-level (multi-level logit) analyses, the study investigates the interplay between parental socioeconomic status (SES) and immigrant status in friendship formation. While rising relative SES among migrants fosters greater inter-group friendships, the analysis also reveals a nuanced mixture of status exchange and status similarity preferences, with the latter exerting a stronger influence. These findings underscore the significance of examining the interplay between status exchange and status similarity preferences in shaping the formation of inter-ethnic friendships among adolescents. The third study examines the integration of Muslim migrants in Western societies, with a focus on how attitudes toward sexual liberalization influence friendship dynamics within school environments. By employing multilevel exponential random graph models (MLERGMs), the study reveals that attitudes toward sexual liberalization play a mediating role in Muslim segregation. Specifically, when controlling for attitude homophily, the study reveals a reduction in the tendency of Muslim migrants to form friendships within their religious denomination. However, despite this mediation effect, a significant portion of religious segregation remains unexplained, emphasizing the need for future research to delve deeper into the underlying factors shaping Muslim friendship segregation

Framing effects in consumer expectations surveys

In a randomized experiment embedded in a survey, I test the effects of variations in question wording and format on consumer response behavior and the corresponding inflation expectations. To this end, survey participants from a representative sample of German consumers are broken down into four treatment groups and presented with different versions of a question asking for their subjective distribution for inflation over the next 12 months. As part of the experiment, two competing wordings, previously known from leading consumer surveys, are considered: (i) the change in prices in general or (ii) the inflation rate. In addition, I compare the responses to a question asking for consumers’ probabilistic beliefs about future inflation, to those from a simpler one asking for the expected minimum, maximum, and most likely inflation rate over the short term. I find that response behavior varies strongly with framing. Simpler wording such as ‘prices in general’ and a less restrictive format lead to higher mean expected inflation, on average. While simpler wording increases individual uncertainty derived from the subjective histograms, asking for minimum, maximum and mode leads to lower uncertainty about expected inflation

Analysis of a capacity-based redispatch mechanism

This paper discusses a capacity-based redispatch mechanism in which awarded market participants are compensated for their availability for redispatch, rather than activation. The rationale is to develop a market design that prevents so-called “inc-dec gaming” when including flexible consumers with a market-based approach. We conduct a game-theoretical analysis of a capacity-based redispatch mechanism. Our analysis reveals that despite its intention, the capacity-based redispatch is prone to undesirable behavior of market participants. The reason is that the availability payment incentivizes participants to change their energy consumption (generation) behavior. However, this also applies to undesired participants who increase the redispatch requirement through participation. Under certain assumptions, the additional redispatch potential equals the additional redispatch demand it creates. Consequently, the mechanism does not resolve network constraints, while causing costs for the compensation payments. Furthermore, we study three alternative implementation options, none of which resolves the underlying problem. It follows from our analysis that a mechanism can only be promising if it is capable to distinguish between the potential participants to exclude the undesirable one