Import Uncertainty and Export Dynamics.

This article investigates the impact of uncertainty in import clearance times on the export dynamics of manufacturing firms in 48 developing countries from 2006 to 2014. Using a novel measure of import uncertainty based on the interquartile range of Customs clearance times and firm-level data, the study finds that unpredictability in the time to clear imported inputs does not affect firms' entry into or exit from export markets but significantly reduces the survival rates of new exporters beyond their first year. This negative effect intensifies over time, is primarily driven by South-North trade reflecting the time sensitivity of buyers in developed countries, and varies across manufacturing sectors, with sunk costs of entry in foreign markets mitigating firms' exit despite uncertainty. The findings highlight the importance of policies aimed at reducing unpredictability in import processing times—such as improving coordination among border agencies, adopting electronic systems, and implementing trade facilitation agreements—to support the sustained participation of developing-country firms in global export markets.