In recent years, the British foreign trade surplus continues to expand to the United Kingdom has brought political and economic lot of problems, but also attracted wide attention from scholars at home and abroad. Research shows that the United Kingdom in the international division of labor in which the position is the main reason for British foreign trade imbalances, namely the United Kingdom in the international production networks play a role in processing and assembly ground, a large number of imported intermediate products are processed and exported to overseas assembly, led to a substantial increase in UK exports. Henryk Kierzkowski and Lurong Chen (2007) noted that today, spare parts trade more frequently than the final product, fragmentation of production and outsourcing has become the norm. Tian (2005) believes that the current development of the newly industrialized countries and the British state has come into the international division of labor, not only in the volume of trade within the product to become a significant growth in international trade reasons, but also a change in the pattern of international trade flows are an important force, a British national industrialization and development of industrial structure upgrading in new ways. Cui Wei (2009) under the United Nations BEC Industry Classification Standard intermediate goods imports to the UK size was estimated that the British imported goods mainly for intermediate inputs, the proportion of total imports reached 60%, the UK has to actively join the international product within the division of labor. Sven. W. Arndt (2007) emphasized that now, more and more products are produced in a number of countries, for the analysis of the bilateral trade balance has gradually lost value considering.
In view of the international division of labor in which the United Kingdom's position, imports of intermediate goods export capacity of the United Kingdom will inevitably have a huge impact, this paper aims to analyze the data size of the United Kingdom and the use of intermediate goods imports panel data analysis of its manufactured goods to the UK exports.
Second, the scale of Britain's imports of intermediate goods
In this paper, intermediate goods imports on British exports of manufactured goods, first need to analyze the size of the United Kingdom imported intermediate goods. Since this article focuses primarily on intermediate goods imports on manufactured exports impact analysis, so the corresponding intermediate goods refers to the production of manufactured goods needed intermediate inputs, based on SITC 2 classification criteria, mainly in categories 7 and 8 categories of products (71,72,73,74,75,76,77,78,79,82,87,88,89 of 13 categories), which defines see Francis Ng, Alexander Yeats (1999). From 1987 to the present, the UK's intermediate goods imports have been expanding, the world's total share of total imports of intermediate goods is improving, where the main choice of 1989, 1999 and 2009, three years of data were analyzed, as shown in Figure 1 .
As can be seen from Figure 1, from 1989 to 2009, in addition to 72 classes and 89 classes total world imports of intermediate goods intermediate goods decreased the proportion of total imports, other categories of intermediate goods imports a substantial proportion radiate upward trend, 2009 most categories of total world imports of intermediate goods imports accounted for more than 5%, in particular 73 class - metal processing machinery, 75 classes - office machines and automatic data processing equipment, 77 classes - Electrical machinery, apparatus and appliances, and parts and 88 classes - photographic equipment and supplies, optical goods, watches and other import share of intermediate goods accounted for 10% of total world imports more than 77 classes and 88 classes even more than 15%, the UK has such intermediate goods imports large scale, enough to show that the UK has become the "world factory", a large number of imported intermediate inputs for processing and then assemble the finished products exported to other countries and regions.
Figure 1 UK share of world imports of all kinds of intermediate goods imports of intermediate goods, the proportion of the total
Source: UN COMTRADE database, and authors' calculations
However, imports of intermediate goods alone of the world's total imports of intermediate goods is not enough to explain the proportion of processing and assembly areas in the United Kingdom has the advantage of imports Revealed Comparative Advantage (RCA) index can give a strong proof. Import export RCA RCA index is an index of deformation, when the RCA index of intermediate goods imports data to be calculated, then the index can be used to determine a country whether parts assembly has a comparative advantage, the formula is:
If more than one explanation i country j product assembly has a comparative advantage, and vice versa, then i country j product assembly has a comparative disadvantage.
According import RCA index formula can be calculated in relation to the United Kingdom intermediate goods processing and assembly industries whether comparative advantage in Figure 2 for the 2009 British imports of 13 categories of manufacturing industries RCA index.
Figure 2 2009 English 13 class manufacturing industries, the import RCA index
Source: UN COMTRADE database, and authors' calculations
As can be seen from Figure 2, 2009 English 73 class - metal processing machinery, 75 classes - office machines and automatic data processing equipment, 77 classes - Electrical machinery, apparatus and appliances, and electrical parts, 87 classes - professional scientific control instruments, appliances and 88 classes - photographic equipment and supplies, optical goods, watches and other import RCA index greater than 1, indicating that the UK's processing and assembly in these industries is a comparative advantage, and corresponding to Figure 1, these imports of intermediate goods industries accounted for the proportion of total world imports is the highest.
Third, imports of intermediate goods exports manufactured goods to the UK Empirical Analysis of Influence
From the above analysis we can see that the UK is huge imports of intermediate goods, and in some manufacturing industries have a comparative advantage on the processing and assembly, which will be on British exports of manufactured goods have a direct impact, resulting in British foreign trade surplus increases. So, what intermediate goods imports to what extent, affected the UK's exports of manufactured goods, this paper uses empirical analysis approach to research.
Here the use of data for the years 1987-2009, using panel data model imported intermediate goods exports manufactured goods to Britain effects econometric model set
Log express values related to the definition of indicators and data sources are shown in Table 1.
Table 1 Variable Definitions and Data Sources
After the first part of the analysis, we can know that the UK imports of intermediate goods and import RCA index can be used to measure the size of the United Kingdom imports of intermediate goods, and these two indicators there is a certain correlation between these two indicators were substituted into the model panel data regression, can measure both intermediate goods imports to the UK's exports of manufactured goods, but also the stability of the model can be tested, so set up two structures the same model. As Britain's manufactured exports by supply and demand factors, the supply-side effects can be used to measure the UK's GDP, while the demand side of the trading partners with the United Kingdom's economic development are closely related, so in the model joined the UK's main trading partners weighted GDP as an explanatory variable, calculated by the 2008 British exports, the top 25 countries or territories purpose weighted GDP. RMB real effective exchange rate is an important factor affecting the British exports, and therefore needs to be placed on the explanatory variables in the model.
In order to avoid the impact of the sequence autocorrelation in the model estimates the number of data pairs of first-order differential, in the table below for brevity, PC means that British imports of intermediate goods for the first difference value indicators, other indicators similar. Upon examination, using a random effects model, the empirical results shown in Table 2.
Table 2 intermediate goods imports to the UK manufactured exports Empirical Results
Note: ***, **, * denote 1%, 5% and 10% significant level, a value of t values in parentheses.
The empirical results comparing the two models can be seen, the coefficient of variation is relatively stable and insignificant, indicating that the model structure more stable. Intermediate goods imports on British exports of manufactured goods is reflected in the PC and the RCA coefficients showed that imports of intermediate goods and the import RCA index of manufactured exports to the UK there is a significant positive effect, that is, the increase in imports of intermediate goods and imported RCA index will rise significantly promote British exports of manufactured goods increased. Intermediate goods imports increased by 1%, the UK manufactured exports will increase by 0.35%, while imports RCA index rose 1 percent, the UK manufactured exports will increase by 0.11 percent. This result clearly shows that the United Kingdom in the international production networks are playing the role of processing and assembly to cause the British manufactured goods exports increased significantly. Britain's GDP and the UK's major trading partner countries equally weighted GDP exports of manufactured goods to the UK produce a positive and significant impact, especially in major trading partner countries GDP, every 1% change will bring British manufactured exports is greater than 1% change, indicating that foreign demand is an important factor UK exports. RMB real effective exchange rate for British exports of manufactured goods there is a significant negative impact that the RMB appreciation would lead to a decline in exports of manufactured goods, the United Kingdom, the results in line with expectations.
This analysis shows that the UK is huge intermediate goods imports and imports of intermediate goods exports manufactured goods to the UK have a significant role in promoting, indicating the UK in the international production networks plays a major role in processing and assembly ground, from Japan, South Korea and other newly industrialized countries for processing and assembly of imported intermediate goods and then final products will be exported to Europe, America and other developed countries and regions. Therefore, the British foreign exports actually contains a large component of other countries, did not quite get the benefits of foreign trade surplus.
近年来，英国的外贸顺差继续扩大到英国的政治和经济带来很多问题，但也引起了广泛关注，在国内和国外的学者。研究表明，英国在国际分工中的位置的主要原因是英国的外贸失衡，即英国在国际生产网络中发挥作用的加工和组装地，大量进口中间产品加工，并出口到海外组装，导致英国出口大幅增加。 ：亨里克Kierzkowski和鹿茸陈（2007）指出，今天不是最终产品，分散的生产和外包已经成为一种常态，备件贸易更加频繁。田（2005）认为，新兴工业化国家和英国国家目前的发展已经进入国际分工，不仅在产品内贸易的体积成为一个显着的增长，国际贸易的原因，也有改变在国际贸易流动格局的重要力量，英国的国家工业化和产业结构的发展以新的方式进行升级。崔嵬（2009年）根据联合国BEC行业分类标准的中间品进口到英国的大小估计，英国进口商品主要是中间投入，占进口总额的比重达到了60％，英国有积极投身国际产品内的分工。斯文。 ·阿恩特（2007）强调，现在，越来越多的产品是在一些国家，为双边贸易平衡的分析已经逐渐失去价值考虑。
从图1可以看出，1989至2009年，除了72类和89类，占世界总进口中间产品的中间产品进口总额的比重下降，其他类别的中间品进口相当大的比例辐射呈上升趋势，2009年大多数种类的中间产品进口占世界进口总额的5％以上，尤其是73类 - 金属加工机械，75类 - 办公室机器和自动数据处理设备，77类 - 电动机械，仪器和用具及零件超过77类和88类，88类 - 摄影器材和供应品，光学器材，钟表和其他中间产品的进口份额占世界总进口量的10％，甚至超过15％，英国有这样的中间产品进口规模大，足以显示，英国已成为“世界工厂”，大量的进口中间投入处理，然后组装成品出口到其他国家和地区。
可以看出，从2009年图2中，英语73类 - 金属加工机械，75类 - 办公室机器和自动数据处理设备，77类 - 电动机械，仪器和用具及零件，87类 - 专业科学的控制手段，电器及88类 - 摄影器材和用品，光学器材，钟表和其他进口的RCA指数大于1，表明，英国的加工和装配在这些行业中是比较优势，并对应到图1，这些进口的中间产品产业占世界总进口量的比例是最高的。