Duan, Shuwen2014-09-122014-09-122014-09-11vt_gsexam:3663http://hdl.handle.net/10919/50497This dissertation describes two essays in empirical international trade, focusing on trade costs and the pattern of trade along the intensive and extensive margins. In the first essay, I study the barriers that impede international trade. In the second paper, I examine the growth of U.S. agricultural trade in detail describing how U.S. agriculture and food trade has expanded along the margins. The first chapter introduces a relatively straightforward, yet empirically powerful, manipulation of the gravity equation. The gravity model has been dubbed the work horse model of empirical trade, and thus is a suitable foundation from which to derive an indirect measure of largely unobservable 'iceberg' trade costs. In this paper, I solve a sector level version of the gravity equation and study the pattern of agricultural trade costs and factors that impede world agricultural trade growth over a long time series, 1986-2011. In addition, I estimate sector-specific elasticity of substitution which is a key parameter in the computation of trade cost. In the second essay, I examine the growth of world and U.S. agricultural exports along the intensive and extensive margins of international trade over the period 1986 to 2010. The purpose of this essay is to decompose the growth of world and U.S. agricultural trade using qualitative methods from the marketing literature (i.e., market expansion grids) but modified to fit bilateral trade relationships and a theoretical index to measure the margins of trade at a single point in time. In addition, we examine often overlooked channels by which U.S. agricultural exports have expanded using very detailed agricultural product lines. Using information related to the pattern of a trade rather than trade volume itself, I estimate how much starting a trade relationship with a new partner or in a new product variety matters to agricultural trade growth and then conclude with a set of stylized facts to inform current theory.ETDIn CopyrightElasticity of SubstitutionAgricultural Trade CostTrade MarginsDissertation