The Center on the Development of the Child at Harvard University released a neat interactive fact sheet about early child hood development.

Most relevant to the early care and learning sector? $4-9 - the returns for every dollar invested in early childhood programs.

"Providing young children with a healthy environment in which to learn and grow is not only good for their development—economists have also shown that high-quality early childhood programs bring impressive returns on investment to the public. Three of the of the most rigorous long-term studies found a range of returns between $4 and $9 for every dollar invested in early learning programs for low-income children. Program participants followed into adulthood benefited from increased earnings while the public saw returns in the form of reduced special education, welfare, and crime costs, and increased tax revenues from program participants later in life."