Introduction
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.

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 .#p#分頁標題#e#
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.#p#分頁標題#e#

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.#p#分頁標題#e#

CONCLUSIONS
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.