For working parents, few things are as scary as choosing the right daycare. Besides separation anxiety, parents worry that their kids might be neglected or develop bad habits. So naturally you'd think all parents would pick the best-rated child care provider they could. Well, you'd be wrong.

In Indiana, more than a third of families who receive child care subsidies use providers that aren't vetted by the state. The state rates providers based on health, safety and education standards on a sliding scale of 1 to 4 in a system called Paths to QUALITY. But about 35 percent still pick providers without the state's stamp of approval. That got officials in Indiana's Office of Early Childhood and Out-of-School Learning wondering what they could do to increase participation.

At the time, the U.S. Administration for Children and Families was awarding grants to governments willing to use behavioral science -- a combination of psychology and economics -- to improve the performance of social programs. So Indiana applied and won funding in 2014 to see if it could successfully nudge parents to choose better child care providers. The result was a 2.1 percentage point increase in the use of high-quality providers.

"We're happy with that percentage," said Melanie Brizzi, who was the director of the Office of Early Childhood and Out-of-School Learning during the study. "We knew that it was going to be hard to get a large movement, and we were [encouraged that this approach] didn't take a lot of time or energy."

  Indiana is the latest to use behavioral science, which is becoming more common in state and local government. For the past six years, the Administration for Children and Families has funded more than a dozen projects in seven states, including Oklahoma. Several of the experiments have resulted in modest successes that state officials consider victories because they come with a small price tag and would be easy to expand.

Indeed, Indiana's experiment was both affordable and easy. The approach boiled down to trying different communication strategies that might encourage greater uptake of high-quality providers. MDRC, a social policy research organization and a federal contractor, designed and evaluated the experiment. About 12,600 families -- all on waiting lists to receive a child care voucher -- were divided into two "treatment" groups and one "control" group. The treatment groups consisted of parents who received a special mailing and a follow-up phone call about quality-rated providers, and parents who only received the special mailing. The control group was made up of parents who received the standard letter and brochure that the state had already been sending to parents.

Playing off the idea of social influence, the special mailing pointed out that "most parents use their valuable CCDF vouchers to pay for the high-quality care you can get from a Paths to QUALITY provider." That's bureaucratese for, "All the other parents are doing it. You should, too."

The state also tried to make the process of selecting a quality-rated provider as easy as possible. The special mailing included step-by-step instructions for picking a provider, as well as a map showing the three highest-rated providers located near a family's home.

The monthly cost of the most elaborate intervention -- the special mailing and a follow-up phone call -- came out to about $1.40 per person.

Before designing the study, the MRDC research team identified a few reasons why some parents hadn't been picking state-vetted providers. For one, they didn't know about or understand the ratings system. Another problem was time: Once parents moved off the waiting list for vouchers, they only had a couple weeks to select a child care provider, limiting their ability to search for the best quality provider in their area. The inconvenience of upgrading was yet another barrier. In some cases, parents had already been paying for child care, but because they were waiting to receive a voucher, they had settled for lower cost, lower quality care; once they came off the wait list, they weren't inclined to change providers.

Among parents who received both the special mailing and the phone call, their choice of high-quality providers was higher than the control group --14.7 percent compared to 12.6 percent. The difference was statistically significant at the 10 percent level, meaning that the higher uptake was probably related to tactics the MDRC employed and not chance. If expanded across the state, MDRC estimates that 810 more children on vouchers would receive high-quality care.

Last month, federal officials released preliminary results from the Indiana experiment at a conference in Washington, D.C. A full report is due out mid-summer.

In the meantime, the Administration for Children and Families has committed to a five-year contract with MDRC to try another set of behavioral interventions in human services, adding to the $4 million the agency awarded in 2014 for pilot projects aimed at state child support agencies.