abstract The article analyzes whether and to what extent regional related and unrelated variety matter for the development of green technology, and whether their influence differs over the technology life cycle. Using patent and socioeconomic data on a thirty-year (1980–2009) panel of US states, we find that unrelated variety is a positive predictor of green innovative activities. When unpacked over the life cycle, unrelated variety is the main driver of green technology development in the early stages, while related variety becomes more prominent as the technology enters into maturity.

中文翻译：

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专业化、多元化和环境技术生命周期

摘要 本文分析了区域相关和不相关的品种是否以及在多大程度上对绿色技术的发展有影响，以及它们在技术生命周期中的影响是否不同。使用美国各州三十年 (1980-2009) 小组的专利和社会经济数据，我们发现不相关的品种是绿色创新活动的积极预测因素。在整个生命周期中，不相关品种是绿色技术发展早期的主要驱动力，而随着技术的成熟，相关品种变得更加突出。