Maryann O'Sullivan is CEO and founder of Preschool California, a nonprofit, nonpartisan organization dedicated to achieve publicly funded, quality preschool opportunity for all California children whose parents want to enroll them.

We have a chance to do something good for our children, and great for our schools, Tuesday. That's when California decides the fate of Proposition 82, which would give every 4-year-old the opportunity to attend voluntary, quality preschool.

Supported by California's kindergarten and elementary teachers, who know firsthand the difference that preschool makes in children's success, this initiative will invest in our kids and strengthen our kindergarten-grade 12 system.

The initiative represents California's most serious attempt yet to ensure that all children, no matter their ethnicity or level of family income, have the chance to start school on a level playing field with their peers. In addition to helping hundreds of thousands of children get a stronger start, preschool for all will give a needed boost to K-12 schools that are struggling to help so many children catch up.

The research is solid and the evidence is strong: Children who attend quality preschool programs are more likely to read well by third grade, to stay on track to high school graduation and succeed in life. These children are less likely to need special education or to be held back a grade, less likely to get in trouble with the law and more likely to support themselves as adults.

Preschool delivers these benefits by taking advantage of a critical window of opportunity for learning. Most brain growth occurs before age 5, when most children enter kindergarten. Preschool comes at a vital time when children soak up learning like sponges. It helps them build valuable pre-reading and social skills. In addition, preschool offers children from non-English speaking homes the chance to build their English skills before they are asked to "sink or swim" in kindergarten.

California is missing out on an opportunity that other states have already seized. A recent Tracy Press editorial "Say no to Prop. 82 rights" (Preschool initiative too expensive") was wrong to suggest that 65 percent of California children are already enrolled in preschool. That statistic jumbles together childcare and preschool programs of very uneven quality. Only about one in five of our children have access to quality preschool, as measured by the training of their teachers.

The rule about preschool for most California families is that it is out of reach. Three out of four publicly funded programs statewide have children waiting in line to enroll. And the average cost for part-day, private preschool in California is $4,022 per year - more than one year of full-time tuition at a California State University campus.

Proposition 82 will not only benefit California's families, but our state's economy. In 2005, economists at the RAND Corp. projected that California would get $2.62 back for every dollar invested in quality preschool for all. The savings come from improvements to the K-12 schools, increased public safety and reduced poverty among better-educated adults. That's why a number of business leaders and the statewide associations of California police chiefs and sheriffs are backing Proposition 82.

Proposition 82 preserves parent choice by allowing programs to be provided by public and private preschools, child-care centers and non-profit providers alike, as long as they meet specified quality standards, including well-trained teachers. Proposition 82 also includes strong accountability measures, strictly capping administrative spending at 6 percent, maximizing funds spent on kids and classrooms and providing for criminal penalties for waste and fraud.

We talk all the time in California about how to turn around the two-decade decline we've seen in student achievement and graduation rates. Now more than ever, we need to make smart investments to build a stronger economy. We can address California's educational and economic woes by providing every child in our diverse state a fair chance to succeed in school. We will be doing the right thing by our children, and theirs.