Teen pregnancies in England fell dramatically after cuts to sex education program funding, according to a new study. 

The analysis, published in the Journal of Health Economics last month, examined the effect of budget cuts to government-run teen pregnancy-prevention programs—including sex education, free condoms, and access to the “morning after pill”—in the last decade.

The results surprised the authors and frustrated sex-ed advocates. 

Between 1999 and 2010 the British government poured hundreds of millions of pounds into expanded access to birth control and sex education through the national Teenage Pregnancy Strategy program. Post-crash austerity cuts in 2008 slashed the program budget by 70 percent. Politicians and activists sounded the alarm: Rates of teen pregnancy would surely jump because of the funding cuts. 

Instead, England saw a nearly 50 percent drop in the under-18 conception rate between 2007 and 2015, to the lowest level since 1969, leading the study’s authors to conclude government initiatives to reduce teen pregnancy may be “counterproductive.” 

“Put simply, birth control will reduce the risk of pregnancies for sex acts which would have occurred anyway but may increase the risk among teenagers who are induced by easier access to birth control either to start having sex or to have sex more frequently,” wrote the study’s authors, David Paton from the University of Nottingham and Liam Wright from the University of Sheffield.

Because austerity cuts to teen pregnancy programs varied in both amount and timing across regions, Paton and Sheffield could compare changes to pregnancy rates alongside varied changes in annual expenditures. They examined data from 149 local districts between 2008 and 2014. 

Their conclusion: More sex education and easier access to contraceptives is not just unhelpful, it’s likely harmful. 

Whereas some anticipated the rates of pregnancy would drop the most in the areas with the smallest cuts, “to our surprise, we found the opposite,” Paton and Sheffield wrote. “Authorities making bigger cuts saw relatively larger decreases in both birth and abortion rates among teenagers.” 

The authors admit correlation does not necessarily equal causation, but note their results held up to a battery of statistical tests that ruled out other factors as explanations, including education, poverty, and the local political party in control. 

While critics are scrambling to find alternate explanations for Paton and Sheffield’s study, some experts have praised the results, saying it “proves exactly what those of us who have specialized in this area have been saying for years,” wrote Jill Kirby, columnist and former director of the Centre for Policy Studies, a conservative think tank.

“For decades we have failed young teenagers by making sex acceptable and facilitating it. … Today, once more, there is clear evidence of a direct correlation between increased sex education and teenagers having more sex. Yet still, the official approach is to insist that sex education—at younger and younger ages—is the only answer to the crisis.”