市场分割与中国城市出口差异

出口贸易是中国经济增长的引擎，也是影响城市经济发展的重要因素。中国城市出口活动强度呈现由东向西逐渐递减的趋势，东部沿海地区的城市群表现最为优异。经济转型背景下地方政府采取的市场分割政策对中国城市出口差异有显著影响。基于新经济地理理论，在企业微观层面使用Heckman选择模型分析的结果表明：① 短期内，国内市场分割程度加剧导致企业因国内市场受限而替代性地进入国际市场以追求规模经济效益，从而通过增加出口企业数量提升城市出口表现；长期来看，市场分割限制了企业的规模经济效益和专业化分工能力，降低了出口企业的生产率和国际竞争力，从而损害城市出口贸易的可持续发展；这一机制还受到企业所有制及地理区位的影响。② 市场分割对企业出口行为的扭曲程度依外资企业、国有企业、私营企业的顺序递增。③ 在中国中部地区，改善省际交通条件有助于缓解国内市场分割对企业出口行为的扭曲作用，在东部和西部地区则不明显。

Market segmentation and exports in cities of China

This paper studies whether and how market segmentation affects exports from cities of China. Some existing research found that market segmentation promotes the export performance of firms in China, which is against what the New Economic Geography theories would predict. Although explanations were provided, these studies did not distinguish between short-term and long-run effects of market segmentation on exporting firms. Neither did they identify the mechanism of such impact. This paper tries to fill this gap. Based on the Chinese Industrial Enterprises Database, we use Heckman models to analyze the micro impacts of market segmentation on firms in 2007. The regression results of Heckman selection models show that market segmentation affects firms' behavior in two ways. Firstly, severe market segmentation reduces the scale of domestic market available to firms. As a result, firms enter the international market as a complementary market to pursue economy of scale. Secondly, market segmentation also restrains firms from specialisation because of the high cost of transporting intermediate goods between different areas. The impacts of these two pathways lead to the result that market segmentation increases the probability of firms' decision to export in the export decision-making stage to pursue economy of scale. After these firms are forced to enter the international market, however, their productivity and competitiveness decrease because they give up specialised production and lose the broad domestic market and are unable to benefit from the economy of scale. The characteristics of exports emerge from the microscopic analysis of firms' exporting behaviors. Market segmentation promotes exports of cities in the short term by increasing the number of exporting firms of a city. However, in the long run, market segmentation decreases the competitive of exporting firms. That is, the effect of market division policy is unsustainable. In addition, the impacts of market segmentation depend on enterprise ownership and geographic locations. The impacts are larger for state-owned enterprises and private enterprises, implying that foreign-owned enterprises hold super-national treatments. For firms in the central part of China, the impacts of market segmentation decrease when the distance from the city where the firms are located to the surrounding cities decreases. This phenomenon does not exist in the eastern and western regions. The role geographic location plays differs between regions, but there is little difference within the groups in eastern and western China. In eastern China, the transportation infrastructure is well developed, so transportation conditions do not seem to contribute significantly to creating market segmentation and therefore improving transport does not help decrease market segmentation. In western China, political barrier may have acted as the main reason causing market segmentation. Thus, improving transportation conditions, which are equally poor across the region, may not help as much as removing political barriers for reducing market segmentation. Although market segmentation promotes export of cities in the short term, it hurts export of firms in the long run. We recommend local governments make efforts to decrease domestic market segmentation to create a healthy environment for exporting firms. Local governments may open markets to neighboring provinces, encourage firms to balance between focusing on domestic and foreign markets, and improve transportation conditions. For cities in western China, it is necessary to take all these measures. In central China, it is more important to build high-quality roads and decrease transport costs.