Abstract: Pre-kindergarten is the first school environment for children to live together. There is a lot of evidence pointing to the benefits of enrollment in this environment on future school performance, especially in cognitive skills. However, the literature is still very limited about the relationship between this first school stage and the development of soft skills. Thereby, this research aims to contribute by measuring the average impact of pre-K on soft and cognitive skills, for children in the seventh grade of elementary school. These skills were measured by the primary research conducted by Joaquim Nabuco Foundation in the year 2018, in which soft skills were measured through SENNA Instrument and the cognitive skills were measured by the grades of the mathematics and literacy tests. The study was done in randomized public schools of Recife, one of the biggest cities situated in Pernambuco state of Brazil. The effects were measured through a two-stage least squares methodology applied to an IV-SLX model, using the pre-K carried out by indirect friends as an instrument. Besides a positive effect on the test scores, I also found that pre-K has a positive impact on conscientiousness and assertiveness soft skills.

Abstract: Early childhood interventions have the purpose of influencing the child’s development, impacting the school performance, life, and labor market outcomes of the child. Children born with low birthweight (LBW) might have a high difficulty in developing cognitive skills. Therefore, children born with low birthweight will probably be the ones who benefit the most from early childhood interventions. This study examines whether pre-kindergarten (pre-K) attendance can compensate for the negative long-term effects of LBW on academic achievement. Previous research suggests that early childhood programs improve cognitive skills, particularly for disadvantaged children. However, the causal relationship between LBW, pre-K attendance, and academic outcomes remains unclear due to potential unobserved confounders. To address this challenge, I employ an instrumental variable approach based on heteroskedasticity. Using data from the Early Childhood Longitudinal Study, Kindergarten Class of 2010–11 (ECLS-K:2011), I analyze test scores from kindergarten through fifth grade to determine whether pre-K mitigates the academic disadvantages associated with LBW. Summary statistics reveal that among children born with LBW, those who attended pre-K exhibit an average test score difference of less than one point compared to the average test scores of normal birthweight children. The OLS results suggested a negative direct effect of LBW on test scores, although this impact is not corroborated with the heteroskedasticity-based instruments. Pre-K does not influence the path between low birthweight and test scores, which may indicate the presence of other channels as possible remediation in this relationship.