With a $2 billion budget surplus and a ranking in pre-K access that continually lags other states, Minnesota could find no better time to make the necessary investments to reach its stated goal that all children are school-ready at kindergarten entry.

Based on current levels of school readiness and decades of research, only a system of universal access to highly effective programs can achieve this goal.

Only 60 percent of Minnesota children from middle-income families begin kindergarten school-ready in multiple domains, compared with 40 percent for children in low-income families. Dramatic increases in proficiency are needed for all children, not just low-income children. This basic fact has been widely ignored in commentaries and policy debates. Even more sobering is that no more than half of middle-income children are proficient readers on the fourth-grade national benchmark. This surely must be addressed in the broadest way by the state and as soon as possible.

A narrowly targeted approach using school-readiness grants and scholarships cannot mathematically achieve Minnesota's universal school-readiness goal. With 40 percent of young children in low-income families, the overall rate of school readiness would increase to only 70 percent even if targeted approaches led to 100 percent of low-income children school-ready.

Affordability is another neglected issue that impacts both low- and middle-income families. Minnesota has one of the highest costs of child care and early education in the nation. A large percentage of middle- and low-income families cannot afford high-quality programs. Even raising the income threshold to 400 percent of the federal poverty line would benefit a large percentage of middle-class families.

A critical mass of research showing beneficial effects of broad and universal access programs demonstrates that Minnesota will gain from a more ambitious approach to pre-K. In the past five years, state and local pre-K programs in Maryland, North Carolina, New Jersey, Georgia, Michigan, Massachusetts and Oklahoma have shown significant gains in school readiness across the economic spectrum without sacrifices to benefits for the economically disadvantaged.

A universal access system can also promote broader changes. My own experience in school and community collaborations shows that opening full-day or part-day pre-K in public schools accelerates school improvement that also benefits the community. By reducing school mobility, school-family partnerships are more likely to take hold.

The most important factor in achieving high levels of school readiness is the effectiveness of the programs. Key elements are certified teachers who are compensated well, small classes, engaging instruction, the provision of comprehensive services, and a built-in structure that provides continuity to kindergarten and the early grades. These are all characteristics of school-based programs, but community-based programs can certainly replicate this effectiveness.

It is often stated that preschool programs yield an economic return of $7 per dollar invested, which is equivalent to an 18 percent annual return. The primary evidence for this is my own study of the school-based Child-Parent Centers, which are currently being expanded in Minnesota. That study was a major research justification for President Obama's Preschool for All Initiative. In St. Paul, for example, we have found that highly effective pre-K produces gains in literacy that are 40 percent larger than "four-star" rated programs. Levels of parental involvement in school also increased threefold in Child-Parent Center pre-K.

But such a return is only possible for programs that far exceed "four stars" on the Parent Aware rating system. There is no evidence that low-income or middle-income families have adequate access to such programs. A universal access system will help establish the necessary foundation that not only promotes school readiness but also later school success.

Arthur J. Reynolds is a professor in the Institute of Child Development at the University of Minnesota and director of the Midwest Child-Parent Center Expansion Project.