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Yonggeun Jung

Publications and source records attributed to Yonggeun Jung.

2 recordsLinked to original sources
arXiv2026

Watching Trade from Space: Measuring Maritime Trade Using Satellite Imagery

This paper combines synthetic aperture radar imagery, nighttime lights, and port characteristics to measure port-level maritime trade using only publicly available data. We evaluate the framework at ports the model has never observed, training on United States ports and testing on European ports and then reversing the exercise, and find that the mapping transfers in both directions. Applying the framework to Russian ports after the 2022 sanctions, we find reallocation, with the Far East the only basin rising faster than the movement common to all Russian ports. The approach complements methods based on the Automatic Identification System: where transponders broadcast, AIS-based estimates track official statistics closely, and after the sanctions the radar keeps recording activity at western Russian ports that disappears from the AIS record, which is where dark shipping concentrates.

econ.GN↗
arXiv2026

Temporal Disaggregation of GDP: When Does Machine Learning Help?

We propose a modular framework for temporal disaggregation of quarterly GDP into monthly frequency, in which the regression step accommodates any supervised learning model while Mariano-Murasawa reconciliation enforces quarterly consistency. Comparing Chow-Lin, Elastic Net, XGBoost, and a Multi-Layer Perceptron across four countries, we find that regularization, not nonlinearity, drives the gains: Elastic Net achieves $R^2 = 0.87$ for the United States when lagged indicators are included, while nonlinear models cannot overcome the variance cost of small quarterly samples. We formalize this tradeoff through regime-switching bias and ridge-regularization results.

econ.EM↗