Abstract: Reasonably measuring the internal operational efficiency of commercial banks and exploring its internal reasons for operational inefficiency are of great practical significance for promoting the sustainable development of China’s banking industry. This article divides the internal business process of commercial banks into three stages, namely deposit absorption, debt allocation, and asset profitability from the perspective of sustainability, liquidity, safety, and profitability in business activities. Then, we construct a complex network structure for operating process of commercial banks, and a complex DN-SBM-DEA (Dynamic Network SBM-DEA) model. Taking 44 domestic and foreign commercial banks in China mainland from 2013 to 2017 as research samples, this article mainly draws the following conclusions: (1)Compared with the SBM-DEA model and NSBM-DEA model, the DN-SBM-DEA model considers both the internal processes of bank operations and the lagged effects of carryover variables, so the measurement results are more reasonable. (2)With the continuous expansion of openness in China’s banking industry, the overall operational efficiency of 44 domestic and foreign commercial banks in China mainland in 2017 slightly decreased compared to 2013. This is mainly due to the decrease in efficiency during the asset profit stage, which is related to the rise in non-performing loan ratios in the banking industry in recent years, due to the downward pressure on China’s economic environment. (3)Chinese banks have a relatively stronger ability to absorb deposits and allocate assets, which is mainly due to insufficient asset profitability. However, foreign banks have relatively stronger an asset profitability, which is mainly due to insufficient deposit absorption and asset allocation capabilities.
Compared with the previous studies, the network structure constructed in this article is more closely related to the internal processes of bank operations, and in the third stage, it considers the impact of non-performing loans, an unexpected output, on asset profitability, making it more reasonable. In addition,previous studies have mostly shared the investment of the first stage in the second or third stage, but the investment of the first stage in the second or third stage is not fully utilized, and the true utilization rate is difficult to know. If treated directly in a fully utilized manner, it may lead to incorrect evaluation results. This article does not directly share the inputs of the first stage in the second or third stages, but rather selects the corresponding input and output variables reasonably based on the characteristics of the stage. However, this article adopts the mainstream approach of setting stage weights and period weights, which means that the importance of each stage (i.e., weight) is considered the same, and the importance of each period (i.e., weight) is also considered the same. This approach has certain limitations in practice, for example, in the business process of commercial banks, the importance of the three stages of deposit absorption, debt allocation, and asset profitability may not necessarily be the same. Therefore, the future expansion direction is how to determine reasonable stage weights and period weights.

Key words: commercial banks, operational efficiency, DN-SBM-DEA model, Kruskal-Wallis rank sum test

摘要： 合理测度商业银行内部经营效率,挖掘导致经营无效率的内部原因,对促进中国银行业的持续健康发展具有重要的现实意义。本文从商业银行经营活动的持续性、流动性、安全性及盈利性角度出发,将商业银行的内部经营过程划分为吸收存款、负债配置及资产盈利三个阶段,并构建了相应的复杂网络结构及复杂DN-SBM-DEA模型。以2013~2017年间我国大陆44家中外资商业银行为研究样本,本文主要得出以下结论:与SBM-DEA模型、NSBM-DEA模型相比,DN-SBM-DEA模型由于既考虑了银行经营的内部过程,又考虑了结转变量的滞后影响,因此测度结果更加合理;随着我国银行业开放程度的不断扩大,2017年我国大陆44家中外资商业银行的整体经营效率与2013年相比略有降低,其主要是资产盈利阶段的效率有所下降导致的,这与近年来我国经济大环境面临下行压力而导致银行业不良贷款率上升有关;中资银行吸收存款能力和资产配置能力相对更强,导致中资银行经营无效率的内部原因主要是资产盈利能力不足,而外资银行资产盈利能力相对更强,导致外资银行经营无效率的内部原因主要是是吸收存款能力和资产配置能力不足。

关键词: 商业银行, 经营效率, 复杂DN-SBM-DEA模型, Kruskal-Wallis秩和检验