In the past few decades a range of human capital theories were developed by economists. In all these, education and training are considered as a prominent aspect of the human capital. Among all influential factors on the education, the role of the family in the allocation of educational expenditure is one of the most important factors. In this research, we investigate whether in gendr discrimination among sibiling is observed in Iranian households. Based on household budget data, we estimate the Engel curve in order to investigate the gender discrimination in the allocation of educational expenditure. Families divided into 6 clusters based on the composition of their children and the tests...