Trade Liberalization, Wages, and Employment in Developing Countries: The Role of Political Economy and the Informal Sector

关于贸易自由化利弊的公开辩论往往集中在贸易改革如何影响劳动力市场的问题上。但是，尽管这个问题在公共政策中很突出，但到目前为止，实证研究还没有提供关于贸易自由化对就业和工资的影响的确凿证据。这反映了与该领域的实证工作有关的两个主要困难。第一个是衡量问题：近年来，发达国家的贸易保护采取了非关税壁垒的形式，这些壁垒本身就很难衡量，如果不是不可能衡量的话。第二个限制是，贸易保护的政治经济学虽然在贸易理论和进口渗透率的实证研究中取得了进展，但在研究贸易改革对工资的影响时，仍然是次要关注的问题。本研究利用哥伦比亚1985至1994年间的贸易自由化，在这些问题上取得了进展。哥伦比亚的贸易改革主要包括多次降低关税，不仅大幅降低了平均关税，还影响了各行业的保护结构。专注于关税的好处是，它们都经过了很好的衡量，而且--与非关税壁垒措施相反--在不同时间具有可比性。该项目的基本思想是将不同行业的关税变化与每个行业的工资和就业联系起来，以调查贸易自由化是否导致关税降幅较大的部门的工资较低，和/或跨部门的劳动力重新分配。通过的框架明确说明了贸易保护的政治经济学。对行业层面调整的关注与以前的文献不同，以前的文献关注贸易政策变化对特定工人特征(最突出的是技能和教育回报)的回报的影响。这些研究关注的是贸易改革的长期后果，在这种情况下，工人所属的行业并不重要。然而，在短期和中期贸易模式中预测贸易改革的影响时，行业从属关系至关重要。这些模型似乎特别适用于发展中经济体(如哥伦比亚)，这些经济体的劳动力市场僵化阻碍了劳动力跨部门流动。与许多其他发展中国家一样，哥伦比亚的特点是拥有庞大的非正规部门，因此本研究的很大一部分内容是分析这一部门的调整过程。特别是，这项研究考察了贸易自由化是否促进了1990年代《S》中记录的劳动力非正规性的增加，以及正规部门和非正规部门的工资和就业是否受到了不同的影响。这项分析利用了哥伦比亚国家规划部提供的有关行业关税的信息，以及1984-1998年期间全国住户调查提供的详细工人水平数据(包括工作场所特征和非正式情况的信息)。虽然这项工作没有试图对收入不平等进行一般性分析，但它对当前关于贸易改革对工资差距的影响的辩论有影响。这一问题在以严重不平等为特点的发展中国家尤为重要。这项工作确定了一个差距的来源，而不仅仅是整个经济体技能溢价的有据可查的增长：在某种程度上，发展中国家的关税减免幅度较大，在初始工资较低的部门，雇用较大比例的低技能工人，这些部门行业工资的下降将对这些工人产生不成比例的影响。同样，由贸易自由化引起的非正规部门扩张--这通常伴随着较低的工资和零福利--可能会加剧不平等。虽然这些考虑并不意味着贸易自由化是不可取的，但它们指出，需要确定在中短期内可能需要调整援助的部门和工人群体。更广泛地说，分析贸易自由化后的调整进程可能有助于理解和解决我们在实践中经常观察到的特定群体对贸易改革的抵制。

The public debate on the merits and perils of trade liberalization often centers on the question of how trade reforms affect labor markets. But despite the prominence of this question in public policy, empirical research to date has offered no conclusive evidence on the effects of trade liberalization on employment and wages. This reflects two main difficulties associated with empirical work in the area. The first one is a measurement issue: in recent years, trade protection in developed countries has taken the form of non-tariff barriers that are inherently hard, if not impossible, to measure. A second limitation is that the political economy of trade protection, while having made inroads in trade theory and empirical studies of import penetration, has remained a second-order concern in studies of the effects of trade reform on wages. This study makes progress on these issues by exploiting the Colombian trade liberalization between 1985 and 1994. The Colombian trade reforms consisted primarily of multiple tariff reduction episodes that not only drastically lowered the average tariff, but also affected the structure of protection across industries. The advantage of focusing on tariffs is that they are both well measured, and -- contrary to NTB measures -- comparable across time. The basic idea in this project is to link tariff changes, which varied substantially across industries, to wages and employment in each industry, in order to investigate whether trade liberalization leads to lower wages in sectors that experienced larger tariff reductions, and/or labor reallocation across sectors. The adopted framework explicitly accounts for the political economy of trade protection. The focus on industry-level adjustment differs from the previous literature that has concentrated on the effects of trade policy changes on the returns to particular worker characteristics (most prominently, returns to skill and education). These studies focus on the consequences of trade reforms in the long run, when worker industry affiliation does not matter. However, industry affiliation is crucial in predicting the impact of trade reforms in short- and medium-run models of trade. These models seem particularly relevant in developing economies (like Colombia) where labor market rigidities obstruct labor mobility across sectors. Because Colombia, like many other developing countries, is characterized by a large informal sector, a significant part of this research is devoted to the analysis of the adjustment process in this sector. In particular, the study examines whether trade liberalization has contributed to the increase in informality of the workforce documented in the 1990's, and whether wages and employment were affected differentially in the formal and the informal sectors. The analysis utilizes information on industry tariffs from the Colombian Department of National Planning and detailed worker level data from the National Household Survey (that include information on workplace characteristics and informality) over the period 1984-1998. While this work does not attempt a general analysis of income inequality, it has implications for the current debate on the effects of trade reform on wage dispersion. The question is of particular importance in developing countries that are characterized by substantial inequalities. The work identifies a source of disparity beyond the well-documented increase in the economy-wide skill premium: to the extent that tariff reductions in developing countries are larger in sectors with lower initial wages, employing a larger fraction of less-skilled workers, a decrease in the industry wages of these sectors will affect such workers disproportionately. Similarly, a trade liberalization-induced expansion of the informal sector, which is typically associated with lower wages and zero benefits, may increase inequality. While such considerations do not imply that trade liberalization is undesirable, they point to the need to identify sectors and worker groups that may need adjustment assistance in the short and medium run. More generally, an analysis of the adjustment process following trade liberalization may help understand and address the resistance of particular groups to trade reforms we often observed in practice.