政府规模问题作为政府经济政策研究的核心问题之一，一直以来都倍受关注，而著名的“瓦格纳法则”正是基于此问题而提出的。它描述了政府公共支出与经济增长间的关系，对政府决策有很重要的借鉴作用，并且过去几十年以来一直都在被国外学者们反复检验。然而，由于受地区和时期差异的影响，使得以往的检验结果不尽相同。基于上述原因，“瓦格纳法则”在中国适用性情况的实证研究就显得尤为重要。本文基于中国省级面板数据，通过利用面板数据模型与面板协整理论的研究方法，对“瓦格纳法则”在中国各省的适用性情况进行了较为全面、系统的研究，从时点变化、省间差异、短期波动、长期均衡几个不同层面上，量化给出了中国省级政府公共支出与经济增长间的关系。本文的实证研究主要包括如下两个层面：首先，分别对改革开放前后（1952-1977、1978-2007）两个时期内“瓦格纳法则”在中国各省的适用情况进行分析，而后依据研究结果进行两时期的比较分析。研究结果表明：在改革开放前的计划经济体制下，中国各省政府公共支出相对固定，基本不随本省人均GDP的增长而产生相应变化，因此，“瓦格纳法则”在此时期内的中国各省并不适用。在改革开放后，中国各省的政府公共支出占GDP比例与本省人均GDP之间存在双向Granger因果关系。短期波动方面，绝大多数省份的人均GDP会使得当年本省政府公共支出占GDP的比例下降，但不同省份的下降幅度不同，不过近些年则情况相反；长期均衡关系方面，就整个改革开放后30年的时间长度来看，各省政府公共支出占GDP的比例随经济增长是有所提高的。由于“瓦格纳法则”本就是对一个较长时期而言的，故以整个改革开放后30年的时间长度来看，“瓦格纳法则”在中国各省（指绝大多数省份）是适用的。不过，就分阶段而言，“瓦格纳法则”在改革开放后的中国各省大致存在开始“反向适用”，近些年又“正向适用”的情形。也就是说，在改革开放后，随着经济的迅速增长，中国各省政府公共支出占GDP的比例逐年降低，但在近些年又逐年升高。其次，考虑到中国经济地区发展不均衡的特点，按照国家对经济发展区域的相关划分原则，将中国各省划分为东部、中部、西部三个地区，对这三个地区在改革开放后（1978-2007）“瓦格纳法则”的适用情况进行比较分析。研究结果表明：在各省人均GDP对本省政府公共支出占GDP的比例拉动作用上，西部明显低于东部和中部，而东部又略低于中部。同时发现，在同一地区，时间变化要比省份间差异对两变量间关系的影响大的多。对改革开放前后的比较分析可以告诉我们：各省政府公共支出应该从本省自身现状和特点出发，同时考虑短期目标和长期规划，本着可持续发展的原则，来灵活的调节各省政府公共支出，以达到更好的拉动本省经济长期稳定增长的目的。对东部、中部、西部三地区间的比较分析可以告诉我们：我国地区间差异较为明显，这种差异主要表现为不同地区处于不同的经济发展阶段。具体说来，东部地区经济发展较为成熟，政府应加大社会保障和服务方面的投入。西部地区经济发展较为落后，政府公共支出应继续加大基础设施建设等投入，以拉动经济又快又好的增长。中部地区经济发展介于前两者之间，政府公共支出应更多从支出结构和方向上考虑。

The well-known Wagner’s Law is introduced for government size, a core-issues of government’s economic policy research which is continuously concerned by people. It describes the relationship between public expenditure of government and economic growth, playing an important role on government decision-making. Wagner’s Law has been tested in the past decades of years, but the result is inconsistent for the differences of area and era. Based on above reason, it is very important to conduct research on the validity of Wagner’s Law in China.We conduct a systematic research on the validity of Wagner’s Law in China with panel data model and panel cointegration theory, which is based on panel data of each province in China. The relationship between the government expenditure of each province and the economic growth is also quantified from the point view of era, area, temporary fluctuation and long-term equilibrium. This paper includes the followed aspects:First, we tested the Wagner’s Law to Chinese provinces before and after the reform and opening-up(1952-1977 and 1978-2007) and made a comparative analysis according as the conclusions. It is indicated that under the planned economy system before the Reform and Opening, public expenditure of government of provinces of china is stable without changing with the increasing GDP, to which Wagner’s Law does not apply in this period. After the Reform and opening, it is indicated that there is two-way Granger causality between the proportion of government expenditure of each province in GDP and GDP per capita. From the point view of temporary fluctuation, the proportion of public expenditure of government in GDP will be decreased for GDP per capita in most provinces, with different decreasing amplitude according to provinces, although it is just the contrary in recent times. From the point view of long-term equilibrium relationship, the proportion of public expenditure is increased with economic development during 30 years of Reform and Opening. So, Wagner’s Law still apply during 30 years’ of development of most provinces, for the law itself is for long-term evolution. But for each stage, there exists a situation that Wagner’s Law applies positively in the beginning and negatively in recent times for most provinces of china after Reform and Opening, means that the proportion of public expenditure decreased first but increased in recent years with the fast economic development after Reform and Opening.Secondly, considering the imbalance in the development of regional economy, we classify provinces of china as eastern, middle and western region according to national dividing principle, and make a comparative analysis on the validity of Wagner’s Law in these regions after Reform and Opening (1978-2007). It is indicated that the proportion of public expenditure in GDP is much lower in western region than that of eastern and middle region, and eastern region is a little lower than middle region. It can also be approved that in the same region, the influence of era to the relationship between two variables is much greater than that of the difference of area.It is discovered from comparison between data before and after Reform and Opening that government public expenditure should be made based on present situation and characteristics, considering both temporal goal and long-term plan according to the principle of sustainable development, adjusted flexibly in order to realize the steady growth of province economy.The comparative analysis on eastern, middle and western region indicate that the regional difference of China is large, different region stay at different economic development era. Economic development is sufficient enough in eastern region and government public expenditure should incline to social insurance and welfare. In the contrary, it should be inclined to basic infrastructure in the western region to make economy develop faster and better. In the middle region, government should adjust the expenditure structure and preference as the economy is in the intermediate situation.