基于泰尔指数的盈利能力差异性测度研究

盈利能力是商业银行稳健性的重要保证。资产收益率(ROA)是衡量商业银行盈利能力的一个重要指标,但其无法直接衡量不同类型银行间盈利能力的差异性,也无法直接体现盈利能力差异不同影响因素的贡献度。基于此,本文的主要工作是在资产收益率的基础上,利用泰尔指数构造了单位资产收益率泰尔指数(ROUAT)与人均收益率泰尔指数(ROPPT)两个指标,用来测度商业银行盈利能力的差异性,并对中国13家上市商业银行2006~2015年的财务数据进行实证。实证结果表明:国有控股银行盈利能力的组内差异远大于股份制银行的组内差异,也大于国有控股银行和股份制银行的组间差异。通过对单位资产收益率泰尔指数(ROUAT)与人均收益率泰尔指数(ROPPT)对比,进一步发现人均收益率差异比单位资产收益率差异表现更为突出,说明现阶段银行的员工人数比银行的总资产对银行盈利能力的影响大。本文的主要贡献是利用泰尔指数和资产收益率构造了单位资产收益率泰尔指数和人均收益率泰尔指数两个指标,解决了不同分组下的商业银行的盈利能力差异性的测度问题,解决了差异性影响因素的贡献度问题,盈利能力差异性的测度为相关部门的政策制定提供参考。

Research on Profitability Difference Based on the Theil Index

Profitability is an important guarantee for the stability of commercial banks.Return on Assets(ROA)is an important index to measure the profitability of commercial banks. However, ROA can neither directly measure the differences in profitability among different types of banks nor reflect the contribution of different factors of profitability differences directly.The main work of this paper is to use the Theil index to construct two indicators——ROUAT and ROPPT on the basis of ROA, which are used to measure differences in profitability of commercial banks.And we have conducted the empirical study on the financial data of 13 listed commercial banks in China from 2006 to 2015. The empirical result shows that the intra-group differences in the profitability of state-owned holding banks are far greater than the intra-group differences in joint-stock banks and also greater than the differences between state-owned holding banks and joint-stock banks.By comparing the index ROUAT and ROPPT, it is further found that the difference in per capita income ratio is more prominent than that of unit asset returns. This shows that at this stage,the number of employees has a greater impact on bank profitability than the total assets. The main contribution of this paper is to use the Theil index and ROA to construct the two indicators of ROUAT and ROPPT , which solves the problem of measuring the profitability of commercial banks under different sub-groups and the contribution of the different influencing factors.The measure of profitability difference provides reference for the policy making of relevant departments.