This dissertation consists of three essays on development economics and international trade. It focuses on topics related to the link between informal employment and formal credit markets, the effect of credit supply shocks on exports, and the relevance of exporter-importer matches on international trade. The first essay, The Effect of Informal Employment on Household Bank Indebtedness in Colombia, measures the impact of informal employment on households' access to and level of bank credit. The results show that households in informal employment are less likely to access the bank credit market and have a significantly lower bank loan amount than households in formal employment. The second essay, Sectoral Dynamics of Colombian Exports during the Financial Crisis, explores the impact of the 2008 supply credit shock on the Colombian sectoral exports. The results suggest that the downturn in banks' foreign financing decreased the domestic loan supply. While the credit crunch harmed manufacturing exporters, there is no evidence of any effect on commodity exporters. The third essay, The Role of Match Age on the Reduction of Penetration Costs: A Trade Network Approach, explores the relevance of long-standing exporter-importer matches on international trade outcomes. The theoretical model with non-uniform penetration costs for the exporter and competition in the variety market reveals that a long-standing exporter-importer match reduces penetration costs and increases the exporter's variety market share.