Hi! I'm an Assistant Professor in the Department of Economics at KU Leuven, and an associated researcher at the Institute for Fiscal Studies.
I'm interested in questions relating to urban and spatial economics, development economics, and labour economics.
*I am currently on parental leave*
Image credits: Binta Zahra Diop, 08/2023
This paper studies the distributional impact of road construction on educational opportunity in Benin, Cameroon, and Mali. I show that roads enable moves to opportunity and move opportunity itself. To capture both channels, I embed a quantitative spatial model with education choice into a place-effects framework and estimate parameters using a movers design and a novel instrument isolating indirect variation in connectivity. Road building since 1970 increased the causal effect of place on primary school completion by 12.5% on average. Moving to opportunity explains 84% of the average effect, but moving opportunity causes 15% of locations to be worse off.
In this paper, we find that high-wage workers sort mainly to high-wage occupations and not to high-wage firms, and that at least half of the previously documented sorting to firms can be attributed to the segregation of occupations across firms. To reach these conclusions, we leverage the universe of matched employee-employer data from France and Germany and estimate a flexible two-way worker-job fixed effects model of log wages. We then isolate worker sorting to firms by studying the within-occupation across-firm covariance between worker and job fixed effects.
This work subsumes a previous paper titled: The Role of Firms and Occupations in Wage Inequality.
To what extent are modern within-state spatial inequalities related to those in the distant past? Using granular data from the Doomsday Book, I show that areas of England that were 10% richer in 1086 are, on average, still between 1% and 2% richer almost 1,000 years later in 2020. This relationship is not mediated by physical characteristics of place, or pre-existing infrastructure, but rather by time-invariant measures of local market access. Using a historical natural experiment, the Harrying of the North, and a dynamic quantitative spatial economics model, I find suggestive evidence that correlated fundamentals rather than path-dependence can explain the observed persistence.
In 1134, a storm created the Zwin, a river connecting Bruges to the North Sea. By 1500, it had silted up and become unnavigable. I exploit this natural experiment to show that whilst open, the Zwin more than tripled Bruges’s population. To measure its long-term shadow, I develop a dynamic quantitative spatial model incorporating merchants and Malthusian dynamics, and build a retrieval-augmented generation large language model to extract merchant data from 120 qualitative historical sources. The model shows that the Zwin altered the distribution of economic activity not just in Bruges, but across the Low Countries, both when navigable and for hundreds of years after.
We examine how cross-border syndication ties reduce information frictions and positively impact exports of equity underwriting services. Using a panel data set from 2000–15, we develop a measure of information flows based on ‘core syndication ties’ where the lead underwriter is in either the importing or exporting country. We find that new core syndication ties have a significant and positive effect on exports. This finding is supported by evidence from ‘peripheral syndication ties’, which are associated with smaller information flows, and an instrumental variable approach which focuses on plausibly exogenous supply-side shocks. Furthermore, the effect of new core syndication ties is stronger when information frictions between trading partners are more severe and for more information-sensitive transactions like IPOs.
We use a parsimonious gravity framework to simulate and compare five potential shocks to the global shipping system: closures of the Panama Canal, the Suez Canal, and the Strait of Malacca, and openings of the Northwest Passage and a hypothetical Kra Canal. Applying a single, consistent methodology across all five scenarios allows relative comparisons. Using carefully measured seaborne distances between ports under each hypothetical geography, we find that a Panama closure would be the most consequential shock, reducing global trade by nearly 3% compared to a default gravity prediction, followed by Suez (2.5%), Malacca, (1.7%), a Kra opening (+0.7%), and the Northwest Passage (+0.6%). Aggregate GDP and welfare effects are more muted, but show sizable heterogeneity across countries. For example, Panama loses over 9% of GDP from a Panama closure, Egypt and Sudan over 5% from Suez, and Malaysia over 4% from Malacca.
Exposure to Chinese import competition led to significant manufacturing job losses in the United States. Local labor markets, however, differ significantly in how they fared with respect to manufacturing employment. An important question is whether labor market institutions have an impact on the dynamic response of manufacturing employment to rising import penetration. We contribute to this debate by showing that minimum wages amplified the negative effect of Chinese import penetration on manufacturing employment in US local labor markets between 2000 and 2007. We develop a rigorous double-edged identification strategy. First, we construct shift-share instrumental variables to address the endogeneity of import penetration. Second, we use a border identification strategy to distinguish the effects of minimum wage policies from the effects of other local labor market characteristics that are unrelated to policy. Specifically, we rely on comparing commuting zones that are contiguous to each other but located in different states with different minimum wage policies. The approach essentially considers what happens to the response of manufacturing employment to import penetration when one crosses a policy border.
In this paper, I study spatial inequality of opportunity measured in terms of the causal effect place has on primary completion, in Benin, Cameroon, and Mali. Using a movers design I find that on average moving to a one standard deviation better location at birth increases a child’s probability of completing primary school by 15 percentage points. Estimating locality-year and gender-locality-year place effects I show that place matters more for girls than boys and place effects are correlated with local characteristics such as urbanization, access to electricity, and employment in agriculture. Religion is weakly correlated with average causal place effects but strongly correlated with the gender gap in the effect place has on educational attainment.
With Chris Wymant, Luca Ferretti, Daphne Tsallis, Marcos Charalambides, Lucie Abeler-Dörner, David Bonsall, Robert Hinch, Michelle Kendall, Mathew Ayres, Chris Holmes, Mark Briers, Christophe Fraser.
The COVID-19 pandemic has seen the emergence of digital contact tracing to help to prevent the spread of the disease. A mobile phone app records proximity events between app users, and when a user tests positive for COVID-19, their recent contacts can be notified instantly. Theoretical evidence has supported this new public health intervention, but its epidemiological impact has remained uncertain. Here we investigate the impact of the National Health Service (NHS) COVID-19 app for England and Wales, from its launch on 24 September 2020 to the end of December 2020. It was used regularly by approximately 16.5 million users (28% of the total population), and sent approximately 1.7 million exposure notifications: 4.2 per index case consenting to contact tracing. We estimated that the fraction of individuals notified by the app who subsequently showed symptoms and tested positive (the secondary attack rate (SAR)) was 6%, similar to the SAR for manually traced close contacts. We estimated the number of cases averted by the app using two complementary approaches: modelling based on the notifications and SAR gave an estimate of 284,000 (central 95% range of sensitivity analyses 108,000–450,000), and statistical comparison of matched neighbouring local authorities gave an estimate of 594,000 (95% confidence interval 317,000–914,000). Approximately one case was averted for each case consenting to notification of their contacts. We estimated that for every percentage point increase in app uptake, the number of cases could be reduced by 0.8% (using modelling) or 2.3% (using statistical analysis). These findings support the continued development and deployment of such apps in populations that are awaiting full protection from vaccines.
With Michelle Kendall; Lucie Abeler-Dörner; Chris Wymant; Luca Ferretti; Mark Briers; Chris Holmes; David Bonsall; Johannes Abeler; Christophe Fraser.
We observed significant decreases in incidence and R on the Isle of Wight immediately after the launch of the Test and Trace programme. The Isle of Wight had a marked reduction in R, from 1·3 before the Test and Trace programme to 0·5 after by one of our measures, and went from having the third highest R before the Test and Trace programme, to the twelfth lowest afterwards compared with other UTLAs. Our results show that the epidemic on the Isle of Wight was controlled quickly and effectively after the launch of Test and Trace.
With Samuel Altmann; Hannah Zillessen; Raffaele Blassone; Frederic Gerdon; Ruben Bach; Frauke Kreuter; Daniele Nosenzo; Séverine Toussaert; Johannes Abeler.
Epidemiological evidence shows that app-based contact tracing can suppress the spread of COVID-19 if a high enough proportion of the population uses the app and that it can still reduce the number of infections if uptake is moderate. We found strong support for the app under both regimes, in all countries, across all subgroups of the population, and irrespective of regional-level COVID-19 mortality rates. We investigated the main factors that may hinder or facilitate uptake and found that concerns about cybersecurity and privacy, together with a lack of trust in the government, are the main barriers to adoption.
Spatial agglomeration, productivity, and inequality. Social Mobility Commission Think Piece. With Monica Costa Dias, and Robert Joyce. 2024
How do the last five years measure up on leveling up? IFS Report. With Christine Farquharson, Imran Tahir, Bobbie Upon, and Gautam Vyas. 2024