The Education Department reported today that the graduation rate at public high schools is the highest since 1974. What does that mean for the overall economy? And the graduates’ earning power?

For starters, high school graduates earn $130,000 more during their lifetimes than dropouts. And, the Education Department says, 78 percent of high school students are now graduating — a number not seen in almost four decades.                       

“If you have less than a high school diploma, you’re likely to make $9 an hour or less,” explains John Gomperts, head of America’s Promise Alliance, an education advocacy foundation. “If you have a high school diploma, you’re likely to make more than $20 an hour.”

Bob Wise is president of the Alliance for Excellent Education. He says Wall Street and Main Street will love these new graduation numbers, because our economy depends so much on consumer spending. We need more of those $20-an-hour graduates.

“Whom do you want walking into your retail mall, into your bank?” he asks. “The $9-an-hour person doesn’t get in there. The $20-, $25-an-hour person is the one that’ll fuel the economy.”

Of course, we still have a long way to go. Minority graduation rates still lag behind. Rufina Hernandez is executive director of the Campaign for High School Equity. She says, for example, almost 30 percent of Hispanic students drop out.

“We’re not going to receive the benefit of their innovation, their skills,” she says.  “And our economy will go further and further and further into decline.”

Because, Hernandez says, more and more of our future workforce will be minority students. Many, now struggling in high school.