Cowan, and Cowan 1990). This scale can be used to characterize parenting in terms of authoritarian, authoritative, and permissive (see Baumrind (1968) and Maccoby et al. 1983).

Finally, we measure expectations about the benefits of a better home environment and quality time spent with children by adapting a scale to elicit these beliefs developed by Cunha, Elo, and Culhane (2013). This instrument asks parents about the age at which they would expect children to achieve developmental milestones in language and socio-emotional development, under different scenarios concerning home environments and parental investments. Our adaptation confronts parents with two scenarios: a high-investment home, in which parents spend quality time cognitively stimulating their children and do not use harsh disciplinary strategies to manage their behaviors; and a lowinvestment home, in which parents do not cognitively stimulate their children often and they rely on harsh discipline. Our hypothesis is that parents in the treatment group may report earlier ages in the high-investment home than those in the control group, because as a result of NEP they are more aware of the impact of home investments on child development.

# 2.3.2 Parental investments in children

To measure parenting behaviors and home environments we combine self-reported and directly observed variables. We use two sub-scales of the Parent Behavior Checklist (Fox 1994), where parents were asked to indicate how frequently they engaged in different activities with their child over the past couple of weeks. A first sub-scale measures Nurturing practices, associated to positive parental socio-emotional interactions with the child. A second sub-scale measures Discipline practices, a mixture of positive and harsh disciplinary practices (an exploratory factor analysis of the Discipline subscale confirmed that these are indeed capture two separate underlying constructs).

In addition, in the baseline survey we administered the Family Care Indicators (FCI) (Hamadani et al. 2010), which measures the frequency of learning and play activities with children, as well as the amount and variety of play and learning materials available at home. In the endline survey we used a revised version of the FCI, with additional self-report and observational items from the HOME-SF (Bradley and Caldwell 1984), enabling us to expand the Family Care Indicators for an older age group. Using these items (which are highly correlated to each other), we construct a latent factor index of cognitive stimulation using all the items using principal components analysis.

# 2.3.3 Child development outcomes

We consider three developmental domains potentially affected by the intervention: language, executive function, and socio-emotional development. Different test instruments available at baseline reached an age limit and endline, and were complemented by measurements that could cover a wider age range.

<u>Language: At baseline we measured both receptive and expressive language for children from 0</u> to 71 months using the Spanish version of the Preschool Language Scale (PLS-4). However, because a large proportion of children at endline were older than 71 months and could not be administered the PLSIV, in the endline survey we applied the “Test de Vocabulario en Imágenes” (TEVI-R), a direct assessment for receptive vocabulary that has been adapted from the Peabody PPVT and normed for the Chilean context and was administered to children 36 months of age and 9