As a very public advocate of parental choice in education for most of my adult life, I am used to having my intentions questioned.

It’s a family tradition. My parents, both of whom were career educators in North Carolina public schools, also advocated school choice as one of several reforms they believed would help more students learn and succeed. As a result, they drew attacks far more vicious and idiotic than anything I’ve experienced. To their credit, my parents shrugged off the criticism for the most part and continued to say and do what they thought was right.

Although some opponents are implacably against school choice because it would weaken their power or subvert their ideological assumptions, I assume that most share my goal of improving educational opportunities for North Carolina children and simply disagree about the means. I think choice and competition are valuable in and of themselves while also making it more likely that other reforms — of teacher and principal preparation, deployment, and compensation, for example — will be enacted and sustained by district-run public schools.

If you disagree in good faith, then by all means let’s have a conversation. I’ll start by saying that one reason I believe school choice is a valuable component of education reform is that I’ve read as much of the peer-reviewed literature on the subject as I could find. More specifically, by my count there have been 139 academic studies published since 1990 that looked at the effects of choice programs that include private schools, plus 75 that examined public-school programs (such as open enrollment, controlled choice, and magnet schools) and another 85 that targeted charter-school performance.

After reading these articles, I categorized them according to whether they found statistically significant effects on test scores, graduation rates, subsequent college attainment, or other measures of student success. I applied a rigorous standard: if, say, a voucher plan produced higher graduation rates among Hispanic students but had no effect on other student groups, I coded the outcome as “mixed or statistically insignificant.” Similarly, if a researcher ran four different statistical tests on the same set of data and found effects in only two of them, I coded that as a mixed result (unless the researcher clearly identified some of the tests as more inclusive or superior than the others).

So here’s what I found. For both choice programs limited to public schools and choice programs including private ones, 65 percent of the research findings were positive and statistically significant. For charter schools, a majority also found positive effects, but the share was less impressive: 55 percent.

This is not a case of older, weaker studies favorable to school choice being supplanted over time by more sophisticated research documenting its ineffectiveness. So far in 2015, I have seen seven peer-reviewed, published studies of private-school choice programs. In five cases, the findings were positive. In the other two, the results were mixed or statistically insignificant. (Almost no studies, old or new, find negative associations between school choice and student outcomes.)

No research question is ever fully answered. As more studies are conducted, policymakers will learn even more about which policies work best, which students benefit the most, and which policies don’t deliver on their promises. We ought to welcome these findings, no matter where they might take us.

At this point, however, there is a large body of empirical evidence, from the United States and around the world, demonstrating that giving parents more choice among schools has real benefits — not just for those receiving direct assistance but also for the system as a whole, because of the salutary effects of competition. Given that choice and competition are integral to the success of other complex human enterprises — including those with substantial government funding such as medical services and higher education — I see the research findings about school choice as unsurprising and commonsensical.

You may strongly disagree. Fine by me. Challenge the methodology. Commission additional studies asking different questions. In the meantime, however, don’t waste your time lecturing or yelling at me. You’re persuading no one and only embarrassing yourself.

John Hood is chairman of the John Locke Foundation. Follow him @JohnHoodNC.