Disentangling the Dynamics of Family Poverty and Child Disability: Does Disability Come First? July 1, 2003November 6, 2018 Porterfield, S. L., & Tracey, C. M. (2003). Disentangling the dynamics of family poverty and child disability: Does disability come first? (CSD Working Paper No. 03-1). St. Louis, MO: Washington University, Center for Social Development.