Gains from Economic Integration: Theory and Evidence from Agricultural Markets

摘要命题：经济一体化的收益：来自农业市场的理论和证据命题编号：SES-1227635首席研究员：戴夫·唐纳森经济一体化的收益有多大？由于研究人员从不观察同时关闭和开放的市场，回答这个问题的根本挑战在于预测当地市场，无论是国家还是地区，在它们突然与世界其他地区或多或少变得一体化的反事实情景下会如何表现。这个项目将开发一种新的方法来了解这种反事实的情况。中心思想是专注于农业，这是一个经济部门，在这个部门中，关于基本投入如何映射到产出的科学知识是唯一被很好地理解的。作为这种知识的结果，农学家能够预测如果一块给定的土地被用来种植一套作物中的任何一种，它的产量会有多大。该项目的方法将这些关于事实和反事实技术的农学预测与一个一般均衡模型结合起来，在该模型中，在完全竞争的情况下，不同类型的地块被分配给多个当地市场上的多种作物。到目前为止，本研究的重点是将这一新方法应用于1880年至2002年美国农业市场的背景。全球农业生态区(GAEZ)项目的农艺数据和美国人口普查的历史数据相结合，确定了美国各州作物价格在一段时间内的空间分布，同时仍允许出现未观察到的作物县年度特定生产力冲击。这些对当地价格的估计进一步确定了贸易成本随时间的变化，进而确定了1880年至2002年期间市场一体化的收益。该项目正在进行的工作采用了类似的方法来研究全球农业贸易改革。尽管农产品贸易对许多发展中国家至关重要，但关于农产品贸易的工作相对较少。这里开发的新方法可能很适合填补这一空白，因为它为这一主题的量化工作提供了一个灵活、易处理和科学知情的框架。其目标将是改善对取消农业贸易政策可能如何影响农产品价格和贸易流动以及生产和消费这些商品的人的福利的预测。这些考虑是世界贸易组织多哈回合谈判的核心。正在进行的第二个领域的工作重点是气候变化的经济后果。由于农业模型(如GAEZ模型)可以在广泛的气候变化情景下重新计算，这里开发的新方法也有可能为各国如何通过改变其产出结构和通过与其他国家的贸易能力来适应农业部门的气候变化提供新的线索。

AbstractProposal Title: Gains from Economic Integration: Theory and Evidence from Agricultural MarketsProposal Number: SES - 1227635 Principal Investigator: Dave Donaldson How large are the gains from economic integration? Since researchers never observe markets that are both closed and open at the same time, the fundamental challenge in answering this question lies in predicting how local markets, either countries or regions, would behave under counterfactual scenarios in which they suddenly become more or less integrated with the rest of the world. This project will develop a new approach in order to obtain knowledge of such counterfactual scenarios.The central idea is to focus on agriculture, a sector of the economy in which scientific knowledge of how essential inputs map into outputs is uniquely well understood. As a consequence of this knowledge, agronomists are able to predict how productive a given parcel of land would be were it to be used to grow any one of a set of crops. The approach of this project combines these agronomic predictions about both factual and counterfactual technologies with a general equilibrium model in which heterogeneous parcels of land are allocated to multiple crops in multiple local markets under perfect competition.To date this research has focused on applying this new approach to the context of U.S. agricultural markets from 1880 to 2002. A combination of agronomic data from the Global Agro-Ecological Zones (GAEZ) project and historical data from the U.S. Census identifies the spatial distribution of crop prices across U.S. counties over time, while still allowing for unobserved crop-county-year specific productivity shocks. These estimates of local prices further identify changes in trade costs over time and, in turn, the gains from market integration over the period from 1880 to 2002. Ongoing work in this project applies a similar approach to study global agricultural trade reform. Despite its vital importance for many developing countries, there is relatively little work on trade in agricultural goods. The new approach developed here is potentially well suited to fill this gap by offering a flexible, tractable, and scientifically-informed framework for quantitative work on this topic. The goal will be to improve forecasts of how the removal of agricultural trade policies may affect the prices and trade flows of agricultural goods, as well as the welfare of those who produce and consume these goods. Such considerations are at the heart of the World Trade Organization's Doha Round.A second area of ongoing work focuses on the economic consequences of climate change. Since agronomic models (such as the GAEZ model) can be re-computed under a wide range of climate change scenarios, the new methodology developed here also has the potential to shed new light on how countries will adapt to climate change in the agricultural sector through changes in their output mix and through the ability to trade with other countries.