1950, when Philadelphia's population hit 2 million for the first time, making it third only to New York and Chicago, also marked a time of great infrastructure investment in the nation. Philadelphians, thinking that their population would only trend up, braced themselves to manage a city of 2.5+ million.
Fifty years later, instead of going up 500,000, it went down 500,000. Manufacturing got mechanized/suburbanized/offshored, the Interstate Highway system helped suburbanize America, and cities got caught in a vicious cycle of job loss, middle class flight, and blight.
Thankfully for cities like Philadelphia, the last decade has largely brought about the end of the transition from industrial economy to knowledge economy. Downtowns have enjoyed a renaissance as places of employment and residence. Energy and environmental considerations have made far-flung suburbs less viable, while dense, transit-rich urban centers have become more compelling.
We may not get to 2.5 million or even back to 2 million, but it has been good to see we are losing population less fast this decade. And it was heartening to read yesterday that we actually probably posted a gain from 2007 to 2008, according to revised Census estimates: +93,000, putting us back over 1.5 million.
While I want to give pats on the back all around to Philadelphia for this piece of very good news, I would be remiss if I did not also at this time offer a recommendation to ensure that there will be more of these gains in future years. If you look at all the cities that are growing, you'll see it's less about retaining existing residents - vibrant cities lose as well as gain - and more about replacing them with new residents, most notably immigrants. New York, Chicago, Los Angeles, Atlanta, Miami, the Bay Area are all destinations of choice for immigrants.
Philadelphia is not in that top tier; but if it gets there, we might just have enough bodies to use all the infrastructure, physical and institutional, that we already in place. If you look at those top tier immigrant destinations, you'll also notice that they're all doing pretty well, too; draw your own conclusion as to cause and effect, but to me it's clear that being very welcoming to people who are making life choices about where they want to live and work will almost certainly lead to a more vibrant economy, job creation, and business formation.