作为世界性的连锁零售企业，沃尔玛与开市客分别位列2021年《财富》世界500强企业的第1位和第27位。本文选取2009~2021年沃尔玛与开市客的营业收入、利润、总资产、店面数和员工人数作为研究样本，通过DEA-Malmquist模型，测算疫情前后沃尔玛与开市客的投入产出效率。通过数据分析结果显示，沃尔玛与开市客产出效率受其技术变化效率影响较大。在此基础上，结合得出的实证结果和经济意义的解释，本文分别提出在疫情时代下优化沃尔玛与开市客企业运营管理措施和提高效用比的建议。

关键词：《财富》世界500强、开市客、沃尔玛、DEA模型、Malmquist指数

As a worldwide chain retail company, Walmart and Costco ranked 1st and 27th respectively in the 2021 Fortune Global 500 companies. This paper selects the operating income, profit, total assets, number of stores and number of employees of Walmart and Costco from 2009 to 2021 as a research sample to measure the input-output efficiency of Walmart and Costco before and after the epidemic through the DEA-Malmquist model. The results of data analysis show that the output efficiency of Walmart and Costco is greatly affected by the efficiency of its technological changes. Combined with the empirical results and the explanation of economic significance, this paper proposes to optimize the operation and management measures of Walmart and Costco and improve the utility ratio in the era of the epidemic.

Keywords: Fortune Global 500, Walmart, Costco, DEA Model, Malmquist Index