e 1.047 1.09 0.957 0.97 0.987
Note: ***p<0.01,**p<0.05, p<0.1; Base period = 2019
The digital transformation of commercial banks
presents significant heterogeneity. Joint-stock banks
and state-owned big banks have structural differences
in the ability to obtain technical dividends. CMB, as
the representative of joint-stock banks, has an average
annual growth rate of total factor productivity (TFP)
of 14.8%, which is significantly higher than the
average of 4.3% of state-owned big banks
(ICBC3.2%, CCB4.1%, BOC5.7%, ABC2.6%). This
difference is due to the flat governance structure of
joint-stock banks, which can respond to technological
changes more quickly. Take CMB as an example, the
average cycle of digital technology from research and
development to commercial use is 11.3 months,
which is 40.2% shorter than that of state-owned banks,
and the average annual growth rate of API interface
transfer is 37.4%, forming a positive cycle of open
banking ecology. There is a nonlinear relationship
between scale expansion and efficiency improvement.
Although ICBC ranks first in the industry with an
asset size of 44.7 trillion yuan, its scale efficiency
value (0.987) is lower than that of joint-stock banks
(CMB is 0.983), revealing the dilemma of
"diseconomies of scale". The deep mechanism
analysis shows that when the bank asset scale exceeds
the threshold of 35 trillion yuan, the management
complexity index increases by 19.7%, while the
resource allocation efficiency decreases by 8.3%,
which requires super-large banks to establish a
dynamic scale early warning mechanism (Berger &
Mester, 2003).
4 CONCLUSION
Through a systematic analysis of the digital
transformation practices of China's five major
commercial banks from 2019 to 2023, this study
reveals the mechanism and boundary conditions of
data factors on bank efficiency. The empirical results
show that the digitalization process of commercial
banks presents significant heterogeneity: the
institutions represented by BOC rely on the intensive
investment of blockchain technology (the frequency
of related terms reached 56 times in 2021), and the
average value of their DEI reached 51.48, while the
ICBCDEI level was only 17.26. This difference is
directly mapped to the dynamic evolution of total
factor productivity (TFP) - CMB achieved a 14.8%
TFP growth rate through the open bank interface
ecological construction (API transfer volume
increased by 37.4% annually), nearly three times
higher than the average of state-owned large banks,
highlighting the catalytic role of market-oriented
mechanisms on the release of technology dividends.
More importantly, the study identified for the first
time the critical value of DEI diminishing returns
(76.3) in the banking industry. When the digital input
intensity (DEI/ assets ratio) exceeds 1.7‰, the
marginal contribution of TFP will turn from positive
to negative due to technical redundancy. This finding
provides a scientific basis for the regulatory
authorities to establish a dynamic early warning
mechanism.
At the theoretical level, this study breaks through
the traditional linear analysis framework, and reveals
the nonlinear relationship between digital input and
bank efficiency by constructing a three-dimensional
interpretation model of "strategic focus - technology
transformation - ecological collaboration". At the
practical level, the conclusion provides an operable
quantitative tool for differentiated supervision: for
large state-owned banks, it is suggested that the
commercialization rate of patents should be included
in the assessment of senior executives (target value >
30%) to shorten the technology transformation cycle;
For joint-stock banks, it is necessary to expand the
technology spillover radius through API interface
standardization (such as ISO 20022 protocol);
Regulators can develop intelligent monitoring
systems based on DEI thresholds to identify excessive
digitization risks (such as DEI/ asset ratio overrun