中国制造业省区间分布的集中与分散研究

利用1980—2000年中国制造业的工业增加值数据,计算并分析各行业的区位基尼系数及其变动趋势,判断各工业行业在省区之间分布的不平衡性及其变化趋势。分析结果发现:①从1980年代到1990年代,我国26个制造业工业行业总体的空间分布趋于集中。12个分散分布型工业行业中有9个分散的程度有所收敛,9个集中分布型行业中有5个集中的程度得到加强,另有5个行业的省区分布由分散型转为集中型;②自然资源的禀赋条件对行业生产的地域集中有较大的影响;③外商直接投资的区位选择偏好及行业投资重点的差异会导致相应投资行业的生产在地理空间上的集中。     

我国企业规模经济现状及实现途径

目前,我国主要产业的企业规模普遍偏小,产业集中度过低,生产要素配置过于分散,缺乏规模经济。合理扩大我国制造业的企业规模,实现规模经济是提高我国工业竞争力的当务之急。以横向联合方式为主的企业购并是短期内实现规模经济的有效途径。     

Advertising, Its Determinants, and Market Structure

This study derives a formal model of firm advertising behavior and applies it to the industry level to figure out the relationship between advertising and market structure. The firm advertising model shows that both consumer preference andfirm-specific advertising competence jointly determineprofit-maximizing advertising intensity. At the industry level, advertising intensity is represented multiplicatively by consumer preference and a measure of market structure, which reflects the joint distribution of the levels of advertising competence and market shares among firms. The new market structure measure suggests that those single-dimensional measures of market structure such as seller concentration and the Herfindahl index are inadequate in explaining interindustry differences in advertising intensity, and that the long-debated advertising-concentration relationship differs depending primarily on the appropriability of advertising. An empirical analysis of 426 five-digit Korean manufacturing industries shows that an inverted U-shaped relationship between the Herfindahl index and industry advertising intensity is observed for consumer goods industries but a lazy J-shaped relationship for producer goods industries.     

Political hazards and firms' geographic concentration

Research summary : We examine the relationship between the geographic concentration of a firm's sales and the firm's vulnerability to expropriation hazards. Although expanding outside the home location can initially increase a firm's exposure to government expropriation, we find that this effect reverses when a firm's sales outside its home location have reached a point at which it has sufficient resources to better influence government actions and to pose a credible threat to exit the market in which it is being targeted. We supplement this main result by identifying two moderating factors: the firm's level of political capital and the effectiveness of institutional constraints on government behavior. We find support for these hypotheses from survey data on privately owned enterprises in China. Managerial summary : This research advises firm managers that certain market activities might knock their firms' economic interests out of alignment with the government's political interests, and thus, influence the political hazards they face, particularly in emerging markets such as China, which has attracted strong interest of many firms with respect to entering the market. Here, all else being equal, the firms' geographic concentration exposes them to different levels of state expropriation—but not in a simple linear fashion as suggested by the conventional wisdom of local protectionism or that of the bargaining advantage generated by the threat of relocation: Those who are “stuck in the middle” ended up paying twice or even three times as much unauthorized levies as the purely local or the most expansive firms. Copyright © 2015 John Wiley & Sons, Ltd.     

"利剑斩污"行动下石家庄市挥发性有机物的污染特性变化研究

为研究石家庄市在"利剑斩污"行动管控期和非管控期挥发性有机物(VOCs)的污染特性变化,在2个时间段内对石家庄市3个国控点进行采样分析。通过苏玛罐(SUMMA罐)进行样品采集,利用气相色谱/质谱联用(GC/MS)仪对石家庄市区3个国控点的VOCs进行定性定量检测分析。结果表明,监测期间主要的特征污染物是二氯甲烷、二氯丙烷、苯和甲苯。与非管控期间相比,管控期间各污染物的质量浓度均有所降低,总VOCs平均质量浓度降低45.107μg/m~3,二氯甲烷质量浓度降低8.796μg/m~3,二氯丙烷质量浓度降低3.750μg/m~3,苯质量浓度降低18.285μg/m~3,甲苯质量浓度降低16.895μg/m~3。大气环境调控策略的实施,有效降低了VOCs浓度,减少了空气污染程度,空气质量改善效果显著。"利剑斩污"行动期间采取的相关举措,对于制定常态化下VOCs的防治对策具有一定的参考价值。     

Are margins more procyclical in concentrated industries?

In a series of recent papers, Domowitz, Hubbard and Peterson (DHP) have explored the temporal behavior of price-cost margins in a panel of 284 four-digit SIC industries. This paper reexamines DHP's apparent finding of more procyclical margins in concentrated industries, concluding that it is not robust. The result appears to arise from long-run trend correlations between margin and demand levels, rather than from short-run cyclical effects. Consistent with DHP, prices are found to be stickier and unit costs more countercyclical in concentrated industries. However, (1) an omitted variables bias is uncovered which substantially reduces the estimated cyclical effect on costs, and (2) prices are found to be more flexible in low concentration, low-PCM industries than DHP estimate. With prices more responsive to growth in demand and a countercyclical effect on cost of substantially lower magnitude, margins are thus estimated to bemore procyclical in less concentrated industries. This finding explains the relative rise in low concentration margins in the sixties which, in turn, helps account for the declining significance of the cross-sectional concentration-margins relationship.I would like to acknowledge helpful comments from Roy Rotheim, and two anonymous reviewers.     

中国制造业产业集聚的实证研究

文章利用集中度、基尼系数、赫芬达尔指数(N指数)等指标,对中国20个二位数制造业门类的集聚性进行了实证研究,并对其中5个门类进行了细化研究,得出结论:中国部分制造业已显现出较强的集中性,且主要集中在东部沿海省市,但一些规模经济和范围经济性强、在国外具有显著集聚特征的行业的集聚性还比较低。     

中国水生蔬菜出口市场集中度和依赖度分析

[目的]水生蔬菜作为我国区域性特色明显的优势农产品,出口创汇能力强。以莲藕、芋头和荸荠为主要研究对象,分析其出口规模、产品结构和市场分布,可全面把握中国水生蔬菜的出口市场形势,有助于防范出口市场风险,以便更好地推进中国水生蔬菜出口市场的进一步优化。[方法]文章通过测算市场集中率和依赖度系数,对2012—2021年中国水生蔬菜的出口市场集中度与依赖度进行分析。[结果]中国水生蔬菜出口市场集中度高,由高到低依次为芋头、莲藕和荸荠;出口依赖性强,其中莲藕对马来西亚、日本、美国的市场依赖性强;芋头对日本、美国的市场依赖性强;荸荠对马来西亚、新加坡和越南的市场依赖性强。[结论]基于研究结果和发现,提出拓展新兴市场、提升质量标准、延长产业链条等建议,以降低水生蔬菜出口风险、提升国际竞争力,推动中国水生蔬菜更好地发展。     

中国蔬菜生产“以水定地”优化布局研究

[目的]文章以中国蔬菜产业布局为研究对象,通过分析蔬菜生产重心演变路径、蔬菜布局地域集中度以及蔬菜生产空间布局与水资源禀赋的拟合度,为优化我国蔬菜生产空间布局、促进农业节水、保障农业用水安全提供参考依据。[方法]采用1995—2018年我国蔬菜产业的相关数据,运用重心模型、集中度指数等方法,对蔬菜生产的区位特征进行研究,并构建蔬菜生产空间布局与水资源禀赋拟合度指标,对蔬菜生产空间布局与水资源禀赋拟合度进行分析。[结果]我国蔬菜生产重心呈现出整体上向西南方向移动的新趋势,蔬菜生产的地域集中度已经达到较高水平,但蔬菜空间布局与水资源禀赋的匹配度不高,导致蔬菜生产过度依赖人工灌溉,消耗甚至是浪费了大量的水资源。[结论]遵循“以水定地”原则,提出蔬菜产业空间布局与水资源禀赋条件优化匹配的政策建议：推进大宗蔬菜生产重心“西南移”,充分利用南方水资源优势,节约北方水资源;推进耐储运蔬菜的“南菜北运”,解决北方消费市场的蔬菜供给问题;推进北方蔬菜生产“转型升级”,转型生产精细时鲜特菜和节水型蔬菜,升级采用微灌、精灌技术,保持北方蔬菜基地经济水平。     

湖州地区辐射影响因子分析

[目的]为了探究湖州地区太阳辐射情况,利用2009年1月至2017年12月湖州国家基本气象站的辐射观测资料、地面常规观测资料以及大气成分观测资料。[方法]文章分析了湖州地区太阳辐射的变化特征,并检验了太阳辐射与部分气象要素极值的相关性。[结果]太阳辐射日变化基本呈抛物线型。6月因湖州地区进入梅雨季节,阴雨寡照,并不是一年中辐射最大的月份,一年中辐射的最大值出现在7月,之后逐渐下降。按季节统计,夏季辐射最大,春季次之,秋季比冬季略高。除了2015年以外,近几年辐射总量平稳中稍有下降,考虑到可能存在的辐射年际变化,并不能就此认为该地区的辐射处于下降趋势中。辐射强度与总云量、低云量、最小相对湿度为负相关,与日最高温度、日最高地温呈正相关。晴天时,太阳辐射强度与颗粒物浓度PM10、PM2. 5、PM1三者相关性基本一致,均为春、秋和冬季呈负相关,夏季呈正相关,两者的关系应该按季节具体分析。[结论]影响湖州地区辐射的因子有很多,部分气象因子相关性较好,颗粒物浓度不能简单看成全年太阳辐射的影响因子。