These findings are consistent with previous empirical studies based on firm-level data, and call for further theoretical explanations.
这些发现与先前的基于企业层面数据的实证研究相一致，需要更进一步的理论解释。
2
The GVC framework represents just one of many approaches to detailed, firm-level research on the structure and dynamics of global industries.
全球价值链的结构仅代表对全球众多行业结构和动力学的详细的公司层面的研究方法之一。
3
Thus, as we review in greater detail in the next section, firm-level and industry-level studies do not provide an empirical foundation for subsidizing SMEs.