Nowadays, sustainability has become an important and widely accepted concept. Energy conservation and emission reduction are closely related to sustainable economic development. Therefore, a 3E efficiency approach, based on the “Energy–Environmental–Economic” (3E) system, can assess the coordination relationships among these three factors from the perspective of energy conservation and emission reduction. The digital economy is a new driving force for economic growth, but few studies have dealt with the question on whether it affects 3E efficiency. The purpose of this paper is to examine the relationship between the digital economy and 3E efficiency in EU countries. The empirical results indicate that: (1) overall 3E efficiency of EU countries showed an upward trend from 2011 to 2019; (2) in terms of the relationship between the digital economy and 3E efficiency, the digital economy has direct and indirect (through economic growth) impacts on 3E efficiency; when GDP per capita exceeds EUR 15,580, the influence coefficient of the digital economy on 3E efficiency changes from negative to positive. This suggests that EU countries with different levels of economic development should adopt different strategies to ensure the simultaneous development of their digital economy and 3E efficiency.

中文翻译：

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数字经济和 3E 效率绩效：来自欧盟国家的证据

如今，可持续性已成为一个重要且被广泛接受的概念。节能减排与经济可持续发展密切相关。因此，基于“能源-环境-经济”（3E）系统的3E效率方法可以从节能减排的角度评估这三个因素之间的协调关系。数字经济是经济增长的新动力，但鲜有研究探讨其是否影响3E效率。本文的目的是研究欧盟国家数字经济与 3E 效率之间的关系。实证结果表明：（1）2011-2019年欧盟国家整体3E效率呈上升趋势；（2）从数字经济与3E效率的关系来看，数字经济对3E效率有直接影响和间接影响（通过经济增长）；当人均GDP超过15580欧元时，数字经济对3E效率的影响系数由负转正。这表明，不同经济发展水平的欧盟国家应采取不同的策略，以确保其数字经济和3E效率的同步发展。