This Doctoral Thesis includes three essays in International Trade, all focused on African exports, either at the firm or product level. The First Chapter studies the determinants of prices set by Tanzanian exporters in foreign markets, and finds significant differences, within firms, across destinations. The Second Chapter analyses how change in market access affects the exporting probability among African exporters. Lastly, the Third Chapter studies a similar question as Chapter 2, but at the firm level, using the Tanzanian firm-level data described in the First Chapter