Econometric Analysis of Non-life Insurance Industry : Changes in the Post-war Insurance System in Japan

产业组织理论并不是一个全新的领域，我们有很多关于几个行业的论文。然而，运用标准计量经济学对日本非寿险业进行研究的论文并不多。我们的目标是弥补这一差距，并将正统的计量经济学方法引入该行业。虽然我们既有历史研究，也有利用计量经济学进行横截面分析，但对日本非寿险业的横截面和时间序列分析方法还没有。在本研究中，我们尽可能长时间地收集战后数据，并对个别保险公司的数据进行调查。然后我们试图了解战后非寿险行业的整体情况。通过建立一个我们称之为面板数据的数据库，运用传统的统计分析方法和正统计量经济学方法对产业组织进行检验。通过面板数据的计量经济学分析，明确了战后非寿险业的一些特征。我们得到了有趣的结果，可以用来检验每家保险公司的战略。在完成本研究之后，我们有可能对寿险和非寿险行业进行比较。这两个行业都长期受到财务省的监管。顺便说一句，现在在日本，我们遇到了非寿险业的剧烈变化。我们正处于保险制度转型的时代，保险制度的特点自然也会发生变化。在不久的将来，在增加数据之后，我们想重新审视产业组织的变化。这项研究的结果是向这一研究迈出的重要一步。

Theory of industrial organization is not a brand-new field, and we have many papers on several industries. However, there are not so many papers on Japan's non-life insurance industry by using standard econometrics. We aim to make up for the gap and to adopt an orthodox econometrics into the industry.Although we have both the historical studies and the cross-sectional analysis using by econometrics, there are no the cross-sectional and time-series approach to the non-life insurance industry in Japan. In this research, we collected the post-war data as long as we could, and investigated the data of individual insurance company. And then we tried to understand the whole picture of the post-war non-life insurance industry. How to get the picture in this research are that we make a database which we called 'panel data', and examine the industrial organization using both the traditional statistical analysis and the orthodox econometrics.This research show the followings.1. Some characteristics of the post-war non-life insurance industry are made clear by econometrics using panel data.2. We get interesting results that could use in examining the strategy of each insurance company.3. After completed this research, we are possible to compare life insurance and non-life insurance industry. Both industries have been under regulations and supervision by the Ministry of finance long time.By the way, now in Japan, we met the drastic changes in the non-life insurance industry. We are in the era of transformation in insurance system, and it is naturally that the characteristics would be changing. In the near future, after adding data, we would like to reexamine the changes in the industrial organization. Results in this research are an important step to such a study.