California Early Education Investments Yield Significant Long-Term Academic Gains in Math and Reading

Evidence is mounting that California’s multibillion-dollar investment in early childhood education is producing significant long-term academic dividends. According to a new study conducted by researchers at UC Berkeley and commissioned by Stanford University, children who participated in the state’s transitional kindergarten (TK) and preschool programs entered elementary school with a distinct advantage that persisted into third and fourth grade.

The study, which followed a cohort of 1.6 million children who began kindergarten between 2011 and 2014, found that those who had access to early education scored 11 months ahead in reading and eight months ahead in math compared to children born just months apart who did not have access to the programs. These results provide a robust defense of the state’s ongoing expansion of early childhood programs, which currently see billions of dollars in annual taxpayer funding.

California’s transitional kindergarten program was established by a 2010 law that took effect in 2012. Originally, it allowed children with fall birthdays to attend an extra year of school before traditional kindergarten. The law also adjusted eligibility for state-funded preschool, effectively opening the doors for more three-year-olds to enroll. Researchers found that this early exposure to a structured learning environment created an “additive” or even “multiplicative” effect, where early gains in knowledge and behavior helped students maximize the value of their later education.

For researchers like Rucker Johnson, a professor of public policy at UC Berkeley and co-author of the study, the data represents more than just test scores. He described the search for “lost Einsteins”—children with immense natural capacity who might never realize their potential without early intervention. Johnson argued that these investments are essential to helping children overcome socioeconomic circumstances beyond their control.

The findings are particularly striking regarding the program’s ability to narrow the achievement gap. Historically, family income at the time of kindergarten enrollment has been a reliable predictor of future test scores. However, the study suggests that TK and preschool can disrupt this trend. For children from low-income families with English-speaking parents, attending TK alone resulted in seven additional months of learning in third-grade reading and math.

The benefits were even more pronounced for dual-language learners from low-income households. Children who attended both preschool and TK and whose parents spoke a language other than English saw gains in fourth-grade math that were five times larger than those who did not attend state preschool. Their reading gains were three times larger. By contrast, children from wealthier families saw smaller relative gains, likely because they already had access to private preschools and other educational resources.

From the perspective of those on the front lines, the academic data mirrors what is happening in the classroom. Marylou Escobar, a veteran teacher at John Muir Elementary in Glendale with 41 years of experience, noted that the difference between TK graduates and other students is immediately visible. Students with TK experience arrive with mastered “soft skills”—they know how to sit on a rug, follow multi-step instructions, and hold a pencil correctly.

Escobar noted that while she still has to teach some children the basics of classroom behavior, such as paying attention for ten minutes or identifying the top and bottom of a page, TK students are already moving into letters and syllables. “They are ready to learn, whereas the other children are preparing themselves to learn,” Escobar said.

As California enters its second year of offering free universal TK to all four-year-olds, the state is facing the logistical challenges of its own success. The 2025-26 state budget allocates approximately $4.1 billion for TK and another $2.8 billion for state preschool. However, enrollment figures for 2025 show that only about half of eligible children are currently enrolled, falling short of initial state projections.

Maintaining the quality of these programs during rapid expansion remains a primary concern. Experts indicate that recruiting a specialized workforce with the training necessary to handle four-year-olds is critical. Unlike higher grades, early childhood education often focuses on developmental milestones that may seem simple—such as a child learning to put on their own jacket—but actually require coordination, memory, and persistence.

While some historical studies have suggested that the benefits of preschool can fade over time, UCLA associate professor Anna Markowitz described the Berkeley-Stanford findings as a “proof of concept” that early education can provide lasting benefits when integrated into the broader school experience.

Looking ahead, researchers hope to follow these students through high school and college. Johnson believes the early foundation will likely translate into higher graduation rates and improved college readiness. He suggests that the excitement for learning and the ability to handle challenges, fostered in those early years, are the factors that carry forward most significantly into a student’s adult life.