Three Essays on Veterinary Drug Maximum Residue Limits

Authors

• Akinbode Okunola, University of Nebraska-LincolnFollow

First Advisor

Elliott James Dennis

Date of this Version

5-2026

Document Type

Dissertation

Citation

A dissertation presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Doctor of Philosophy

Major: Agricultural Economics

Under the supervision of Professor Elliott James Dennis

Lincoln, Nebraska, May 2026

Comments

Copyright 2026, Akinbode Okunola. Used by permission

Abstract

This dissertation consists of three essays: the first examines the prevalence of veterinary drug maximum residue limits (MRLs), the regulatory behavior of countries in setting these MRLs, and the degree of country-level compliance with international standards of Codex Alimentarius (Codex). The second evaluates the extent to which compliance with international standards across countries can help to manage potential transmission of resistant bacterial from animals to humans through consumption of contaminated meat, dairy and aquaculture products. The third focuses on how differences in regulatory standards across countries can impact international trade in the global beef, pork, and poultry markets.

The first essay analyzes the distribution of maximum residue limits (MRLs) on veterinary drugs used in animal production and aquaculture in a global context of food consumption and trade. The results show that international standards by Codex cover a small fraction (27%) of existing drug-product pairs. When Codex MRLs exist, regulatory compliance is high and deviations from Codex MRLs are minimal. On average, I observe little protectionism although countries with a larger presence on world markets and with larger net imports in the regulated commodity have stricter standards.

The second essay studies the public health dimension of veterinary drug regulation within a One Health framework. It integrates the World Health Organization’s human medical importance classification of antimicrobials with the World Organization for Animal Health’s veterinary classification to construct a hierarchical medical importance framework and a novel One Health Score (OHS). Among medically classified drug pairs, 53% involve Highly Important Antimicrobials for humans and Veterinary Critically Important Antimicrobials for animals. While at least half of the countries comply with Codex at each medical importance level, 21% of countries have laxer standards for the most medically critical drugs.

The third essay evaluates the trade effects of veterinary drug MRLs in global beef, pork, and poultry markets using a structural gravity model that separately identifies the demand-enhances and supply-restricting effects. The results show that stricter importing-country MRLs significantly increase import demand by 39%, consistent with reduced information asymmetries and stronger consumer confidence, while bilateral regulatory divergence systematically reduces exports by 10%. The positive net market effects of 29% indicate the trade gains from exporter compliance with stricter MRLs in destination markets dominates the trade costs