Code and Data for: Measuring Upward Mobility

We conceptualize and measure upward mobility over income or wealth. At the core of our exercise is the Growth Progressivity Axiom: transfers of instantaneous growth rates from relatively rich to poor individuals increases upward mobility. This axiom, along with mild auxiliary restrictions, identifies an ``upward mobility kernel" with a single free parameter, in which mobility is linear in individual growth rates, with geometrically declining weights on baseline incomes. We extend this kernel to trajectories over intervals. The analysis delivers an upward mobility index that does not rely on panel data. That significantly expands our analytical scope to data-poor settings.

本研究对收入或财富维度的向上流动开展概念界定与量化测度。本研究的核心为增长累进公理（Growth Progressivity Axiom）：将瞬时增长率从相对富裕群体转移至相对贫困群体，可提升向上流动水平。该公理结合温和的辅助约束条件，可识别出仅含单个自由参数的“向上流动核函数（upward mobility kernel）”，其中流动水平与个体增长率呈线性关系，且对初始收入赋予几何递减的权重。本研究将该核函数拓展至区间内的动态轨迹场景，最终推导得到无需依赖面板数据的向上流动指数，这极大地将研究分析范畴拓展至数据匮乏的应用场景中。