Related and unrelated variety as regional drivers of enterprise productivity and innovation: A multilevel study
对挪威数据的多层次分析发现，相关产业多样性促进企业创新，而不相关多样性抑制企业生产力，区域专业化（低不相关多样性）则提升生产力。
We conduct multilevel analyses of Norwegian data and find that related industrial variety is a positive regional driver of enterprise innovation. Unrelated variety is a negative regional driver of enterprise productivity. This implies that regions with high levels of related variety and low levels of unrelated variety optimize enterprise performance. We argue that regional specialization is a two-dimensional construct inversely associated with related and unrelated variety. Thus, a specialized region (low in unrelated variety) is in fact a driver of enterprise productivity. In addition, we find that population density is another regional driver of enterprise productivity.