Colloquia department of Sociology

External colloquium Extern colloquium by Prof. Grace Cruz from University of the Philippines Population Institute. This colloquium takes place on Thursday, November 13, from 11:00 to 12:30h.

Location: M.0074 (Noordam room, Munting building)

Abstract:  Prof. Grace Cruz proposes to deliver a presentation on Philippine demographics, with a particular focus on population ageing and related issues. This presentation will draw on findings from her ongoing project, the Longitudinal Study of Ageing and Health in the Philippines (LSAHP)

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Presentation by Dr. Justin Weltz (Santa Fe Institute, Duke University). The presantion takes place on Tuesday, November 25, from 15:00 - 17:00.

Location: B. 126 (Gadourek room, Bouman building)

Title: Studying the Social Networks of Hard-to-Reach Populations

Abstract: Across the social and behavioral sciences, there is interest in how relationships shape individual welfare. However, in many contexts, collecting data on social networks is difficult because the relevant population is inaccessible with conventional sampling methodologies. This talk will focus on two methods for studying the social networks of these “hidden” or “hard-to-reach” populations. First, we will discuss respondent-driven sampling (RDS), which is widely used to study marginalized or stigmatized populations by incentivizing study participants to recruit their social connections. The success and efficiency of RDS can depend critically on the nature of the incentives, including their number, value, call to action, etc. Standard RDS uses an incentive structure that is set a priori and held fixed throughout the study. Thus, it does not make use of accumulating information on which incentives are effective and for whom. We propose a reinforcement learning (RL) based adaptive RDS study design in which the incentives are tailored over time to maximize cumulative utility during the study. We show that these designs are more efficient, cost-effective, and can generate new insights into the social structure of hidden populations. Second, we will address hard-to-reach populations in community social network surveys. In many settings, only specific members of a household, such as the household head, can be accessed and queried about their social connections. This makes a complete census impossible and results in an incomplete sampling frame for the social network. To remedy this issue, we explore how questions that address household behavior, such as the exchange of household goods, can be leveraged to fill in missing information about community members who cannot be sampled.

Internal colloquia 2025 - 2026

During each colloquium, one of the research clusters will give an update on current research and present plans for future research. All internal colloquia take place at the Orangerie (G.026) in the Gadourek building followed by a joint lunch.

The colloquia are planed on: