扩大中等收入群体是实现共同富裕的现实路径,是促进我国未来经济发展的必然要求。选取1985-2015年时间序列数据,建立可变参数状态空间模型,实证分析了产业结构变迁、人力资本水平、R&D(研究与开发)强度、对外开放水平对扩大中等收入群体的动态影响。研究结果显示:产业结构变迁逐渐成为我国扩大中等收入群体的重要驱动因素;人力资本水平对中等收入群体有明显的促进作用但呈现持续地弱化趋势;对外开放水平对中等收入群体的拉动作用趋于强化;R&D强度对中等收入群体的影响弹性为负值,亟待提高R&D投资效率和投资规模。 Expanding middle-income groups is a realistic path to realizing common prosperity and an inevitable requirement for promoting our country’s future economic development. This paper chooses the time series data of 1985-2015 to establish the variable parameter state space model and empirically analyzes the dynamic changes of industrial structure, human capital, R & D intensity and the level of opening to the expanding middle-income group. The results show that: the industrial structure change has gradually become an important driving factor for expanding middle-income groups in our country; the level of human capital has a significant role in promoting middle-income groups but shows a continuous trend of weakening; the level of opening-up tends to middle-income groups Strengthen; R & D intensity on the impact of middle-income groups elasticity is negative, urgent need to improve R & D investment efficiency and investment scale.