An alternative method for calculating relative mobility inspired by Dahl and DeLeire (2008) and first used by Chetty et al (2014). In this method, Let Ri denote child i’s percentile rank in the income distribution of children and Pi denote parent i’s percentile rank in the income distribution of parents. Regressing the child’s rank Ri on his parents’ rank Pi yields a regression coefficientpPR = Corr(Pi,Ri), which we call the rank-rank slope. The rank-rank slopePR measures the association between a child’s position in the income distribution and his parents’ position in the distribution. When compared against intergenerational elasticity of income, the Rank-Rank Slope method has been lauded for being more statistically robust.