Studies that performed cost-benefit analysis of specific early childhood developmental intervention programs in specific locales and their estimated benefit-cost ratio in comparison to our analysis model.

Table 3: Studies that performed cost-benefit analysis of specific early childhood developmental intervention programs in specific locales and their estimated benefit-cost ratio in comparison to our analysis model.

Studies	Age at which cost-benefit analysis was performed (years)	Benefit-Cost ratio
Perry preschool program [39]	27	7.16^*
Chicago child parent center [11]	26	10.83^*
Abecedarian preschool project [39]	22	2.69^*
Bolivian preschool program PIDI [30]	60	2.93
Preschool program in Turkey [49]	65	2.18
Incredible years parenting program [2,10]	30	13.3
Our analysis	65	4.16

^*Cost benefit analyses done at the specified ages and projected over life time to obtain the benefit-cost ratio. Chicago Child Parent Center - projected through 65 years of age).