Working Paper
Why Do Poverty Rates Differ From Region to Region?

This paper proposes a semi-parametric method for poverty decomposition, which combines the data-generating procedure of Shorrocks and Wan (2004) with the Shapley value framework of Shorrocks (1999). Compared with the popular method of Datt and Ravallion (1992), our method is more robust to misspecification errors, does not require the predetermination of functional forms, provides better fit to the underlying Lorenz curve and incorporates the residual term in a rigorous way. The method is applied to decomposing variations of urban poverty across the Chinese provinces into three components – contributions by the differences in average nominal income, inequality and poverty line. The results foreground average income as the key determinant of poverty incidence, but also attach importance to the influence of distribution. The regional pattern of the decomposition suggests provincial groupings based not entirely on geographical locations.