Leiboyu Xiang - Research

Working Papers:

Sowing Cities: Agricultural Innovation and the Geography of Structural Transformation. (Job Market Paper) [Draft]

Abstract: Agricultural technology raised farm productivity and released labor from farming. But does non-farm employment grow in the places where productivity rises? I study this question using the diffusion of higher-yielding rice varieties from 1976 to 2015 in China. By using a new manually collected rice approval records, I build a shift-share technology exposure measure, which combines local rice suitability with national variety diffusion. Using five waves of census data, I track migration and employment across counties, prefectures, and provinces. This paper find technology exposure pushed workers out of farming everywhere. For rural workers with one standard deviation more exposure, the probability of leaving the home province rose by 1.7 to 3.8 percentage points. Within prefectures, farm employment fell most in counties without industry, and their non-farm employment did not replace it. Across prefectures, non-farm employment grew more where industry was already larger, mostly among local workers. Those who left followed established routes to industrial destinations. Thus, although rising non-farm employment shares suggest widespread structural transformation, the employment gains are unevenly distributed across space.

Conference: CCER Summer Institute and the Global South Development Conference 2026

From Paddies to Poppies: Drug Deregulation, Land Competition and Food Security in Historical China. (with Han Wang)

Publications:

Finding Stars: Mapping the Geography of the World's Scientific Elites. (with Andrés Rodríguez-Pose and Neil Lee)

Transactions of the Institute of British Geographers, 2026

Abstract: This paper presents the first systematic city-level mapping of global scientific talent, analysing the top 200,000 star scientists across 3635 cities worldwide annually between 2019 and 2023. We use a novel Knowledge Generation Index (KGI) that combines researcher quantity with research impact to reveal extreme spatial concentration in knowledge production. Just four cities—New York, Boston, London and the San Francisco Bay Area—host 12% of the world's star scientists, while much of the Global South remains virtually excluded from frontier research. Beijing's ascent into the global top 10 represents a rare challenge to established hierarchies. Our analysis uncovers striking disciplinary variations. Resource-intensive fields like clinical medicine cluster heavily, and traditionally dispersed disciplines are increasingly gravitating towards major hubs. Despite these differences, concentration is intensifying across most scientific fields. Even the pandemic's remote collaboration experiment failed to level the playing field. Established innovation centres continued strengthening their advantages while peripheral regions fell further behind. Overall, we find that geography remains destiny, with profound implications for innovation policy confronting widening spatial inequalities in global scientific capacity.

Featured: LSE Impact Blog, 2026; Centre for Economic Performance, LSE, 2026; Shanghai-Hong Kong Development Institute / SHKDI Urban China / Fudan Development Institute, 2026

Policy Reports:

"Where the Water Flows", 2026, Asian Infrastructure Finance 2026, Asian Infrastructure Investment Bank, Chapter 6

Works in Progress:

Global Disparities in Water Quality Monitoring. (with Chunping Xie and Yuhang Pan)
Remoteness and Food Price Vulnerability: Evidence from International Oil Price Shocks in Sub-Saharan African Maize Markets. (with Enqi Zhang and Cong Peng)