This thesis aims at providing rigorous micro-foundations for explaining detailed firm and product level trade flows. In this research I investigate the mechanisms by which firms break into foreign markets and the impact of “\(entry\)” on \(growth\), \(further\) \(entry\) and \(exit\), as well as the potential biases when measuring the export growth of firms using annual data. Specifically, I introduce Quarter-Year, Month-Year and Week-Year estimations and examine whether there are certain countries that act as launch pads for Argentinean firms to target exports. My results provide an accurate measure of export growth and have implications for trade policy. I introduce the concept of “trade liberalisation externalities” whereby bilateral trade liberalisation can lead to an expansion of trade to third countries via the process of sequential exporting. This research also deals with the relationship between exporting, importing and product quality.