The Causal Effect of Family Size On Child Outcomes : Evidence from Ghana

Health is an important attribute of child development and integral to achieving the third Sustainable Development Goal (SDG 3). The literature asserts that there is a trade-off between quantity and quality of children within a family and this has implications on child health outcomes. However, there is little evidence of family size on child health outcomes such body mass index-for-age, weight-for-height, weight-for-age, and height-for-age in Ghana. The paper investigates the causal effect of family size on child health outcomes using data from the Demographic and Health Survey for Ghana from 2003 to 2014 by filling in the gap left in the literature on developing countries. To address the endogenous variations in family size, two main instrumental variables were used separately; (a) twin birth and (b) sex compositions of siblings. In general, on average the results showed a 0.22, 0.28, 0.49, and 0.47 standard deviation reduction in body mass index-for-age, weight-for-height, weight-for-age, and height-for-age respectively when family size increases. This findings confirm the widely assumed negative relationship between quantity and child health with a larger adverse impact of family size on child health relative to what is mostly found in studies on developed countries. Heterogeneous analysis revealed that there are differences among rural and poor households