Abstract
This paper focuses on the question if having a stepsibling means worse academic performance. The assumption is that the distribution of resources (financial, social and cultural) between children is based on biological preferences whereby parents devote more resources to their own children.
According to this hypothesis children with stepsiblings are in a worse position (resource-wise) than children with only full siblings. This paper presents the selected results of exploratory analysis of two-child family using panel data from PISA-L 2003.
The net effect of sibling relationships is examined using coresidence of siblings and family structure. The descriptive statistics suggest that living with both biological parents and stepsiblings can be disadvantageous for children with stepsiblings.