Pittsburgh is a pretty small place. You can get from one end of town to the other in minutes (traffic, of course, permitting). And our social networks are even closer.

But greater Pittsburgh extends far beyond our little corner of Western Pennsylvania. There are hundreds of thousands of self-identifying Pittsburghers across the country and around the world.

Over the past decade, thousands of people have moved into the Pittsburgh area each year, but an average of 40,000 people have left: a Little Pittsburgh the size of Mt. Lebanon being sent into the diaspora each year.

There has been much wailing and gnashing of teeth among Pittsburghers about Pittsburghers moving away. It has evidenced itself in our development strategies, our advertising campaigns, our political messages. Every May, the region wrings its hands as it watches new college graduates run off to the coasts. I say: Let them leave.

People leaving the Pittsburgh region is not a new phenomenon. My grandfather left McKeesport to work in Washington during the Kennedy administration. In the '80s, my parents moved to Columbus after my father graduated from Penn State, which is why my birth certificate comes from the Buckeye State, though I was raised in the South Hills. People have left this region for decades, and will continue to do so.

What should change is our perception of Pittsburgh expatriates. They aren't losses to the region; they are tremendous assets. They are some of our most lucrative exports, branded in black and gold. They have experiences, knowledge, money, time and energy that shouldn't be discounted simply because they don't live in the 412 area code.

Our region's growth will come not from trying to keep people in Pittsburgh, but from capitalizing on a highly mobile culture. Pittsburgh should be the physical epicenter of a much larger reality: people moving freely, bringing with them their ideas and experiences, allowing for new developments to occur.

Some people will stay in the Pittsburgh region; others will leave and later return to start a new family or open a business; still others will leave and never return. But they all will remain connected to a Pittsburgh that is not just a place, but a people.

What Pittsburgh needs to do is keep in touch with its expatriates. The mayor of Louisville used to hold "Louisville reunions" across the country, taking Kentucky bourbon, promotional material and open arms to fellow Louisvillians. Pittsburgh political, business and civic leaders could do likewise on their many travels to promote the region. They also could tap the expertise and varied experiences of expats by inviting them to join advisory boards and take part in civic initiatives.

As for the expats -- your city needs you! Give your time, energy and resources to a region you still love, even if you don't live there anymore. Shop online from Pittsburgh-area establishments. Invest in Pittsburgh businesses. Donate money or online time to Pittsburgh cultural or social-service institutions. Suggest what Pittsburgh can do better. Meet up with fellow expats at the local Steelers bar. Don't forget that you can still contribute to the Pittsburgh region, wherever you are.

As I write this, I'm one of you. I came to Washington, D.C., to go to college and am now sitting in my Dupont Circle apartment. I may come back to Pittsburgh; in fact I would like to. But I could just as easily wind up in Pasadena or Paris or a hundred other cities.

That wouldn't mean I'm any less of a Pittsburgher. But Pittsburgh needs to keep me -- and hundreds of thousands of other expatriates -- engaged in the life of the city. Don't cry over losing us, leverage us as assets.