A common finding in the international trade literature is that economic integration leads to export diversification. By documenting a positive link between joining the European Economic and Monetary Union and bilateral export concentration, the leading essay shows that this is not always the case. Using a panel data approach, I find that exports between the Eurozone members are on average more concentrated than those among countries which do not share the euro. Central to this outcome is that some economic integration agreements, such as the European Economic and Monetary Union, may lead to a drop in not only trade but horizontal FDI costs as well. Theoretically, the results can be explained by the substitutability between exporting and horizontal FDI within a two-sector, two-firm type model which allows for sectoral trade cost heterogeneity. Since the early 1970s, a series of international environmental agreements (IEAs) were signed, ratified, and enforced throughout the developed and developing nations. Regarding IEAs as potential barriers to trade, the second essay seeks to quantify their impact on industry-level exports by using a gravity regression approach. I proceed by classifying industries into dirty and clean based on their average emission intensities and find that the ratification of IEAs is associated with a significant reduction in export flows. The decrease is more pronounced for industries which are classified as dirty or for those which are characterized by high emission intensities per unit of output. Additionally, climate change IEAs bring about a compositional shift towards cleaner exports. Lastly, climate change and acid rain IEAs are found to engender leakage effects. No such evidence is recovered for ozone depletion accords. The third essay adds to the literature on the Kyoto protocol and the carbon content of bilateral trade. It does so by analyzing the effect of ratifying the Kyoto protocol on exports, the carbon dioxide (CO2) intensity of exports, and the CO2 emissions embodied in exports within a novel dataset of 149 countries. For parties that took on binding emission caps, the ratification of Kyoto protocol leads to (i) lower CO2 emissions embodied in exports, (ii) lower CO2 emission intensities, but (iii) higher overall exports. For the same group of countries, a year-by-year analysis underlines a permanent decline in both the CO2 emission intensity and the CO2 content of their exports. Furthermore, the analysis also points out to a short-run decline in exports. In the long run, however, exports are estimated to recover. Also, the commitment type or whether a party was designated as a transition economy at the time of ratification are found to shape the above three outcomes.