Children's development, including brain development, and the differences, both physical and emotional, that children go through as they transition to kindergarten. Reviews of the different forms have evidence concluding that these programs have short, medium and long-term benefits which suggests that the effects are often greatest for the most disadvantaged children. “Some of the data emerging from the model research has produced exciting results in terms of improving educational outcomes and earnings and reducing welfare dependency and crime.” (Currie, 2001). “So much so that the cost-benefit analysis of these programs suggests that they would ultimately pay for themselves in terms of cost savings to the government if they produced even a quarter of the long-term gains of the model programs.” (Currie, 2001). This is one reason why the government has poured large sums of money into these programs—in fact, Obama recently announced a billion-dollar investment in early childhood education. “Obama said that fewer than a third of 4-year-olds enrolled in preschool and blamed the high cost of these programs for essentially cutting off access for infants, toddlers and children. poorer preschoolers. “ (Obama announces $1 billion investment, 2015, p. 1). “He said studies repeatedly show that children who receive early education are more likely to do so