Diego F. Leal

Assistant Professor of Sociology
University of South Carolina

Department of Sociology
University of South Carolina
911 Pickens St., 
Sloan College, Rm. 216
Columbia, SC, 29208
leald [at] mailbox [dot] sc [dot] edu

Sociogram Responsive image

Data and Code Repository

PUBLISHED ARTICLES

1) Visualizing Feminized International Migration Flows in the 1990s

Data and Code

The supplemental material associated with this article published in Socius contains links to all the necessary data and code to replicate the results presented in the paper. The code requires R to run.

2) Fear & Greed in Network Reciprocity, Implications for Cooperation among Organizations

Simulation program & mathematical supplement

This is an agent-based model (ABM) I published in PLOS ONE with other collaborators. Click here to download the simulation program I created for this paper (requires NetLogo to run). You can also click here to download the mathematical appendix.


DISSERTATION WORK

Diffusion as the Bridging of Cultural Holes: An Agent-Based Computational Model

Abstract

In this paper I develop a theoretical model to understand how liminal agents can act as cultural brokers that have the potential to make segregated networks more compact by means of bridging cultural holes. I first develop a critical perspective on liminality and cultural brokerage, always emphasizing that the capacity to span cultural boundaries is a socially learned skill. I then combine the principles of consolidation, influence, and selection to generate artificial societies with tunable levels of segregation across a bright symbolic boundary. After doing so, I simulate diffusion dynamics based on threshold effects in the context of relatively small societies. Results show that, due to their cross-cutting ties, cultural brokers are more effective than popular agents (agents with high degree centrality) or structural brokers (agents with high betweenness centrality) to diffuse an innovation widely. The interrelationships between culture and social network positions are discussed in the final part of the paper.

Simulation program

Click here to download: (1) the simulation program I created (requires NetLogo to run); (2) the model pseudo-code; and (3) A presentation I did at the 2017 International Network of Analytical Sociologists Conference explaining the model and its main results.

This chapter is available upon request. Please e-mail me at leald [at] mailbox [dot] sc [dot] edu


International Migration Flows in the Americas, 1960-2000: A Story of Network Inequalities

Abstract

In this paper I develop an unprecedented description and explanation of international migration flows in the Americas based on the network inequalities that sustain them over time. Using novel data and state-of-the-art statistical techniques, I harmonize bilateral migrant stock data and relevant demographic data on total population, deaths, and births in order to estimate migration flows between the countries in the Americas. I then provide a detailed historic account of these flows by focusing on the following migratory subsystems: Central America and the Caribbean, North America, and South America. Finally, I use network and migration theories, as well as novel Temporal Exponential Random Graph (TERG) models, to explain the evolution of migration flows over time. In particular, I show that international migration in the Americas exhibits very strong network inequalities at the level of triads.

Code

Click here to access the appendix of this chapter. In the appendix you will find: (1) the code (requires R to run) to reproduce all the analyses; (2) all the necessary input data files; and (3) some interesting figures related to sensitive analyses, robustness checks, and goodness-of-fit tests.

This chapter is available upon request. Please e-mail me at leald [at] mailbox [dot] sc [dot] edu