본 연구에서는 우리나라 대형통신기업을 대상으로 2000년에서 2019년까지의 경영효율성을 측정하고 비교하였다. 그리고 도출된 경영효율성지수와 경기변동간의 상관관계에 대하여 실증분석을 하였다. 발견 된 사실들을 정리하면 다음과 같다. 1)우리나라 대형통신기업은 지난 20년간에 걸쳐 경영효율성수준이 하락하는 경향을 보여주었다. 2)통신 3사 중에서 SK텔레콤이 가장 높은 경영효율성을 보여주고 있고 KT 가 가장 낮은 효율성을 보여주고 있다. LG유플러스는 중간수준의 경영효율성을 보여주었다. 3)우리나라 통신3사는 규모의 수익 면에서 수익감소적인 경향을 보여주고 있으며 2010년 이후로 이러한 경향은 더욱 뚜렷해지고 있다. 4)통신3사의 경영효율성과 경기변동과의 상관관계에서는 매출역모형에서는 순경기순 환적으로 나타나고 있으나 부가가치모형에서는 역경기순환적으로 나타나고 있다. 5)통신기술의 도입과 통신시장 세계화에 대비하여 대형통신기업들의 경영효율성을 높일 수 있는 정책대안을 시급하게 강구해야할 것으로 생각된다.

This study was conducted on financial data of 38 economic groups listed on Vietnam’s stock market for the period 2009 – 2019 and it aims to provide an empirical evidence on the impact of working capital management policy on performance in all phases of the economic cycle of Vietnamese economic groups. The study uses FGLS estimation method with 2 dependent variables ROA, GOP, independent variables including INV, AR, AP, CCC, dummy variable representing different phases of the economic cycle, variables Control includes CAT, CR, LEV, SZ, GR. Research shows that the greater the level of investment by companies in liquid assets corresponding to a certain level of activity (shown by average days of inventory (INV), average days of collection. (AR), cash flow cycle (CCC)) the lower the rate of return on assets. The study also provides additional evidence of the negative effects of economic crisis on the performance of economic groups. The study also shows that the number of short-term asset cycles has a positive impact on operational efficiency, and the level of debt use has a negative impact on operational efficiency. This result implies that the managers of economic groups can increase the efficiency of businesses through a reasonable working capital policy.

In this paper we examined a novel extension of the convergence empirics for the maritime business cycle which considers structure breaks and/or changes. To provide theoretical justification, the convergence hypothesis uses the relaxed assumption to technology shocks. Based on the recent empirical results provided by Kim and Chang (2020), we consider nonlinear dynamics that capture the properties on structural changes in the equilibrium adjustment process. This approach bridges the gap between the theoretical framework and empirical specifications. In particular, we applied the convergence hypothesis to the multiple structure change model for the maritime business cycle. Our application to the maritime data showed support of the convergence hypothesis allowing multiple structure changes during the high volatile period and offers additional insight into the forecasting maritime business cycles.