As a man traveling alone, Professor of Social Work Richard Estes has been approached by his share of prostitutes.

But none of this prepared the child-welfare advocate for what he encountered while at a conference for child advocates in Jakarta, Indonesia, a few years ago.

“There was this intersection with 15 to 30 [child] prostitutes on each corner, all managed by a pimp. And the pimps pursued me, trying to ply their wares.

“Can you imagine crossing the street to get something from the store and the pimps descend on you? It really made me angry.”

So much so that when he returned to the States, he decided to look into the problem of commercial sexual exploitation of children in North America.

Armed with seed money from the federal government, Estes and Center for Study of Youth Policy Fellow Neal Alan Weiner enlisted the help of Mexican and Canadian scholars to study the phenomenon in the North American free-trade zone.

In all, the researchers interviewed child prostitutes, their customers and the people who profit off of them in 28 cities, 17 of which were in the United States. The cities chosen were all either major vacation destinations — what Estes termed “sun and sand” cities like San Diego — or major convention cities like Chicago. Philadelphia, where Estes began his project, was one of the 17.

What the researchers found out surprised them. Their findings, released Sept. 10 to much fanfare in the press, shattered several myths about the problem.

“What I didn’t expect were the sheer numbers of children involved” in the sex trade, Estes said. The researchers estimated that from 240,000 to 300,000 children in the United States are at risk for exploitation due to their status as runaways or throwaways.

And contrary to popular assumptions, most of them are neither poor nor black. “Sixty to 70 percent of the children we met were white and from working- and middle-class homes,” Estes said.

One reason Estes took on this project is because the subject is shrouded in secrecy in the United States. When he spoke with social-service agencies in Philadelphia, he said, “We were stunned to find out that [they] knew little about it.”

The press was equally stunned to find out what Estes learned. “You could see it on the faces of the camera crews at the press conference.”

Estes hopes that once the initial shock wears off, policymakers will take action to address the problem. Instead of arresting the kids, he said, “the police should focus on the johns and the people who are making money off the kids.” He advocates sending the customers to special schools where they learn the consequences of their actions. Such schools already exist in San Francisco and Las Vegas, and the repeat offense rate in those cities is only 3 percent for john-school graduates, he said.

As for the kids, “they need a tremendous range of services. But at the moment, the police only contribute to their re-victimization,” he said, with their policy of arresting children for sex offenses.