Age at Preschool Entrance and Noncognitive Skills before School - An Instrumental Variable Approach

We estimate the effect of age at preschool entrance on crucial noncognitive skills in the year before school starts. Using an instrumental variable approach and exploiting cut-off dates for the time at preschool entrance we find that children entering preschool earlier in life have better noncognitive skills in terms of being more assertive and being more able to form friendships. Hence, our results offer general empirical evidence for the non-linearity in the skill formation process. Moreover they show that entering preschool at an early age is an important prerequisite for the development of social school readiness.