arXiv subjects

Rafael Prieto-Curiel

Publications and source records attributed to Rafael Prieto-Curiel.

26 records · Page 2Linked to original sources

arXiv2025

Modeling Urban Population Dynamics and City-to-City Migration

Migration plays a crucial role in urban growth. Over time, individuals opting to relocate led to vast metropolises like London and Paris during the Industrial Revolution, Shanghai and Karachi during the last decades and thousands of smaller settlements. Here, we analyze the impact that migration has on population redistribution. We use a model of city-to-city migration as a process that occurs within a network, where the nodes represent cities, and the edges correspond to the flux of individuals. We analyze metrics characterizing the urban distribution and show how a slight preference for some destinations might result in the observed distribution of the population.

physics.soc-ph↗

arXiv2024

Detecting the sensitive spots of the African interurban transport network

Transport systems are vulnerable to disruption. This is particularly true in Africa, where there are large areas with few highways and heightened risk of violence. Here we attempt to estimate the costs of violent events on African transport in order to understand the way that it may be limiting integration between regions. In the absence of detailed data on trade or migration, we quantify the cost of violence by relating observed incidents to imputed spatial interaction between cities. We produce indices representing the expected intensity of violent events $μ$ and the expected strength of interaction $ν$ between cities in the African interurban network. We estimate the intensity of conflict in a city and, considering the network of all highways on the continent, use a gravity model to generate flows between pairs of cities. We systematically compare $μ$ to $ν$ and classify areas according to their combined impact and intensity. Results show that certain cities and roads in the network contain outsize risk to Africa's transportation infrastructure. These cities have a high propensity for subsequent violence against civilians, and given their role in the network, they also substantially affect regional connectivity and thus economic integration. According to our model, removing just ten edges due to conflict would require rerouting 32$\%$ of trips. The top 100 edges where violence is likely to happen account for 17$\%$ of all trips. We find that cities with the highest $μ-ν$ risk are typically small and medium size with large degree, meaning they act as hubs. Vulnerable areas tend to be characterised by the presence of terrorist groups like Boko Haram in Nigeria or Al Shabaab in Somalia.

physics.soc-ph↗

arXiv2024

Healthcare Utilization Patterns Among Migrant Populations: Increased Readmissions Suggest Poorer Access. A Population-Wide Retrospective Cohort Study

Equal access to health ensures that all citizens, regardless of socio-economic status, can achieve optimal health, leading to a more productive, equitable, and resilient society. Yet, migrant populations were frequently observed to have lower access to health. The reasons for this are not entirely clear and may include language barriers, a lack of knowledge of the healthcare system, and selective migration (a "healthy migrant" effect). We use extensive medical claims data from Austria (13 million hospital stays of approximately 4 million individuals) to compare the healthcare utilization patterns between Austrians and non-Austrians. We looked at the differences in primary diagnoses and hospital sections of initial hospital admission across different nationalities. We hypothesize that cohorts experiencing the healthy migrant effect show lower readmission rates after hospitalization compared to migrant populations that are in poorer health but show lower hospitalization rates due to barriers in access. We indeed find that all nationalities showed lower hospitalization rates than Austrians, except for Germans, who exhibit a similar healthcare usage to Austrians. Although around 20\% of the population has a migration background, non-Austrian citizens account for only 9.4% of the hospital patients and 9.79% of hospital nights. However, results for readmission rates are much more divergent. Nationalities like Hungary, Romania, and Turkey (females) show decreased readmission rates in line with the healthy migrant effect. Patients from Russia, Serbia, and Turkey (males) show increased readmissions, suggesting that their lower hospitalization rates are more likely due to access barriers. Considering the surge in migration, our findings shed light on healthcare access and usage behaviours across patients with different nationalities, offering new insights and perspectives.

physics.med-ph↗

arXiv2024

Geographical Isolation as a Driver of Political Violence in African Cities

Violence is commonly linked with large urban areas, and as a social phenomenon, it is presumed to scale super-linearly with population size. This study explores the hypothesis that smaller, isolated cities in Africa may experience a heightened intensity of violence against civilians. It aims to investigate the correlation between the risk of experiencing violence with a city's size and its geographical isolation. Over a 20-year period, the incidence of civilian casualties has been analysed to assess lethality in relation to varying degrees of isolation and city sizes. African cities are categorised by isolation (number of highway connections) and centrality (the estimated frequency of journeys). Findings suggest that violence against civilians exhibits a sub-linear pattern, with larger cities witnessing fewer casualties per 100,000 inhabitants. Remarkably, individuals in isolated cities face a quadrupled risk of a casualty compared to those in more connected cities.

physics.soc-ph↗

arXiv2023

How international research teams respond to disruption in their mobility patterns

Combining social network analysis with personal interviews, the paper examines how the social structure and internal composition of three Africa-focused international research networks contributes to their resilience. It shows that research networks are structured around a small number of highly influential coordinators. This structure facilitates information exchange and trust between countries and across fields. The study also suggests that the surveyed teams tend to exchange information or trust each other irrespective of their social and professional attributes, indicating that diversity is key to understanding their responses to major shocks such as the COVID-19 pandemic. In a second part, the paper analyzes how the spatial constraints imposed by distance and borders affect their ability to function internationally. It shows that the probability of exchanging information, trusting each other, and co-publishing decreases considerably with distance and that research communities are more likely formed inside the same country than internationally. Interviews reveal that teams responded to travel bans and border closure by emphasizing what they already did best, suggesting that resilience should be considered as an evolutionary attribute of a system.

cs.SI↗

arXiv2023

The diaspora model for human migration

Migration's impact spans various social dimensions, including demography, sustainability, politics, economy and gender disparities. Yet, the decision-making process behind migrants choosing their destination remains elusive. Existing models primarily rely on population size and travel distance to explain flow fluctuations, overlooking significant population heterogeneities. Paradoxically, migrants often travel long distances and to smaller destinations if their diaspora is present in those locations. To address this gap, we propose the diaspora model of migration, incorporating intensity (the number of people moving to a country) and assortativity (the destination within the country). Our model considers only the existing diaspora sizes in the destination country, influencing the probability of migrants selecting a specific residence. Despite its simplicity, our model accurately reproduces the observed stable flow and distribution of migration in Austria (postal code level) and US metropolitan areas, yielding precise estimates of migrant inflow at various geographic scales. Given the increase in international migrations due to recent natural and societal crises, this study enlightens our understanding of migration flow heterogeneities, helping design more inclusive, integrated cities.

physics.soc-ph↗

arXiv2023

Large cities are less efficient for sustainable transport: The ABC of mobility

The use of cars in cities has many negative impacts on its population, including pollution, noise and the use of space. Yet, detecting factors that reduce automobile dependency is a serious challenge, particularly across different regions. Here we model the use of different modes of transport in a city by aggregating active mobility (A), public transport (B) and cars (C), thus expressing the modal share of a city by its ABC triplet. Data for nearly 800 cities across 60 countries is used to model car use and its relationship with city size and income. Our findings suggest that outside the US, longer distances experienced in large cities reduce the propensity of active mobility and of cars, but public transport is more prominent. For cities in the US, roughly 90\% of its mobility depends on cars, regardless of city size. Further, income is strongly related to automobile dependency. Results show that a city with twice the income has 37\% more journeys by car.

physics.soc-ph↗

arXiv2023

Reducing cartel recruitment is the only way to lower violence in Mexico

Every year, Mexican cartels lose many members due to conflict with other cartels and arrests. Yet, despite their losses, cartels have managed to increase violence for years. We address this puzzle by leveraging data on the number of homicides, missing persons and arrests in Mexico for the past ten years, along with information on the interactions among cartels aiming to estimate the size of cartels' population. We model recruitment, incapacitation by the state, conflict and saturation as the reasons why cartels vary in size. Results show that by 2022 cartels have between 160,000 and 185,000 units, becoming one of the top employers in the country. Recruiting at least 350 people per week is essential to avoid their collapse due to the aggregate effect of incapacitation, conflict and saturation. Furthermore, we test the effects of two policy scenarios aimed at decreasing cartel violence. We show that given the state of violence, increasing current levels of incapacitation leads to a rise in homicides and cartel members. Conversely, reducing recruitment provides substantial benefits in terms of violence reduction and decreasing cartel population, calling for structural investments in a proactive strategy that targets individuals at risk rather than a traditional reactive approach centred around incapacitation.

physics.soc-ph↗