Job Market Candidate 2025/26
JMP | CV | javier.boncompte.19 at ucl.ac.uk
PhD candidate at University College London. My research interests lie in Industrial Organization and Applied Econometrics, with a focus on studying firms behaviour and competition dynamics. I am affiliated with the Centre for Microdata Methods and Practice (CEMMAP) at the Institute for Fiscal Studies (IFS).
My references are: Lars Nesheim (UCL), Joao Granja (UCL), and Pierre Dubois (TSE).
Shaping More Than Prices: Corrective Taxes with Product Reformulation
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How do corrective taxes work when firms can reformulate products to avoid them? I develop an equilibrium model of product reformulation to study product responses to the 2018 UK Soft Drinks Industry Levy, a multi-tiered tax targeting excessive sugar content. The model isolates the role of reformulation by using interactive fixed effects to account for multiple endogenous unobserved product characteristics, allowing counterfactuals that revert products to their pre-reformulation attributes. I find the levy reduced sugar sales by 22% and led firms to reformulate more than one-third of products, cutting average sugar content by 40% while lowering product quality, differentiation and tax liabilities. Reformulation benefits nearly all consumers, with gains concentrated among lower-income households and modest losses at the top. Larger firms reformulate a greater share of their products and protect profits more effectively than smaller ones. Overall, reformulation reduced sugar intake relative to a no-tax baseline but also constrained the tax’s ability to further curb consumption. My results show product responses are first-order for welfare and harm reduction, and that multi-tier taxes leverage them more effectively than the non-tiered taxes commonly applied to sugar-sweetened beverages.
Customer Uptrading, Relational Frictions, and Exporters’ Growth
with Oscar Perello
Show AbstractHow do exporters grow their customer networks when maintaining relationships is costly? We study the role of customer churning in exporters’ growth. Using detailed firm-to-firm data from Chilean customs, we show that fast-growing exporters systematically drop buyers that purchase smaller volumes and replace them with large customers, a process we term Customer Uptrading. A formal decomposition reveals that uptrading, rather than selling more to existing customers or expanding the number of buyers, is the main driver of exporters’ growth. Exploiting variation in direct flight availability, we find that exporters maintain longer relationships when better connected to their buyers, linking uptrading to the upkeep costs of managing multiple trade relationships. We rationalize these findings with a dynamic model of network formation in which firms engage in costly customer search and actively decide which relationships to keep or sever, taking into account the upkeep costs of their network. The model predicts that more productive firms both search more intensively and replace more customers than less productive ones, highlighting the central role of search in exporters’ growth and also its limits.
The Diffusion of Tracking Technologies and the Online Advertising Market
with Simeon Duckworth, Giuseppe Forte, and Lars Nesheim
Python implementation of several Interactive Fixed Effects (IFE) estimators for panel data. Includes methods for both balanced panels (Bai, 2009) and unbalanced panels (Bai et al., 2015; Cui et al., 2022), with a focus on computational efficiency.
CORE Econ Interactive Lecture on Inflation
Interactive lecture on inflation and central banks designed for CORE Econ , featuring dynamic visualizations and real-time Q&A powered by Voici; a free, open-source, serverless tool for delivering interactive R and Python simulations to large scale classrooms. Successfully tested with over 80 students simultaneously.