비모수적 규모수익 관점에서 살펴본 항만산업 일반창고업종의 경쟁력

초록

The ‘MPSS’ (most productive scale size) represents the input and output scale at which average productivity is maximized, under the assumption that RTS vary locally (i.e., the frontier is convex and positively sloped). The pair of [input-oriented RTS, output-oriented RTS] is defined as an ‘RTS category’. Within the context of multiple MPSSs, there are seven categories of RTS. The pair [IRS, DRS] is classified as an ‘ambiguous RTS’, rendering decision-making impossible. In other words, this category of RTS exists in a region where the input-oriented RTS and output-oriented RTS are not the same; specifically, the input scale exceeds the largest MPSS, while the output scale falls below the smallest it. An ambiguous RTS that frustrates decision-making can hinder rational investment decisions, growth, and long-term competitiveness due to the inability to predict the precise scale of production. In this context, if the DMU’s category of RTS is ambiguous (i.e., a pair [IRS, DRS]), it can be inferred that this DMU's current level of competitiveness may not be sustainable. A core concern of this study is to validate the sustainability of competitiveness in the port warehousing sector by utilizing the results of DEA. Furthermore, the findings from the sensitivity analysis based on marginal efficiency, along with the MPSS estimation through the efficient isoquants frontier, will be considered. The empirical analysis employs data on sales, operating income, the number of permanent employees, and capital stock from 112 port companies for the year 2023. The number of permanent employees and capital stock are commonly used as input variables in DEA, while sales and operating income are analyzed separately as output variables. The assessment of competitiveness is facilitated by the introduction of the concept of an ‘average virtual company’ which represents the port warehousing sector. This term employs the arithmetic mean of the input and output variables of real companies as its exogenous variable and serves the role of a DMU in DEA. Empirical results of sales and operating income reveal several common findings regarding the competitiveness of the port warehousing sector. These findings can be summarized as follows: low productivity of factors (i.e., labor, value added, and capital) and technical efficiency, which result in a lack of growth drivers; exposure to the ambiguous RTS category of a pair [IRS, DRS]; and unrealistic outcomes from sensitivity analysis and MPSS estimates of input variables. In conclusion, it is evident that the competitiveness of the port warehousing sector could not remain competitive without proactive restructuring efforts.

키워드