# 1 Introduction

A large body of research shows that there are high potential returns to early childhood programs, especially when they are targeted to disadvantaged families (Heckman 2006; Heckman and Masterov 2007). However, not all early childhood interventions are equally successful. Early childhood interventions have a larger chance of producing long lasting impacts when they also lead to permanent changes to parental behaviors, which outlast the duration of the program. When this occurs, and the quality of the environments in which children grow up is changed, we can see as a result sustained changes in child health, cognitive and socio-emotional skills. Examples of interventions which have produced long-term impacts on child development and where home environments played a key role in these changes are Abecedarian (Campbell and Ramey 1994) or the Jamaica Study (Gertler et al. 2014; Grantham-McGregor et al. 1991).

This paper documents the medium-term experimental impacts on home environments and child development of a low-cost and short duration group parenting program, which was delivered at scale in Chile. This program aims to affect child development by promoting sustained changes in parenting behaviors. The program is the Chilean adaptation of the Canadian program “Nobody is Perfect”, which has operated in the Canadian public health system for more than 30 years. The adapted version of the program is called “Nadie es Perfecto” (NEP hereafter).

NEP aims to improve the quantity and quality of parental investments in children by providing parents with the information, motivation and self-confidence to implement positive parenting behaviors. This program is delivered by trained local public health workers who organize weekly group sessions with caregivers of children of 0-5 years old, using an experiential learning model through group discussions. We show that, despite its short duration and intensity, the program produces impacts on home environments and children’s language development, lasting well beyond the conclusion of the program.

Our data come from a large-scale field experiment with two treatment arms and a control group. Parents in the control group have access to regular health preventive services offered by the primary health care system.<sup>2</sup> Parents in the first treatment arm (NEP-Basico, or NEP-B) are invited to participate in a group-parenting program where only caregivers are allowed to attend the meetings (no children), consisting of 6 to 8 weekly group sessions with 6-12 caregivers. The second arm (NEP-Intensivo, or NEP-I) complements the caregiver-only sessions with two additional structured sessions where children participate together with their parents, and which are focused on the importance of language and play. The target population are parents with children aged 0 to 5 who are enrolled in the public health system, especially those who are particularly vulnerable, such as adolescents, single parents, and geographically or socially isolated households.

The duration of the intervention is short, and our focus is on its medium-term impacts, measured long after program completion. A full program cycle of 6-8 sessions lasts only for two to three months. We administered a baseline survey in 2011, right before parents in the treatment groups received the invitation to participate in the program, and re-surveyed the same parents and respective children in 2014, three years after the conclusion of these households’ participation in

> 2 The national child health care program includes services such as developmental screenings, vaccinations, nutritional supplementation and regular check-ups until the child is 6 years old.

2