In case you haven't been paying attention, urban centers are getting more and more powerful.  Over the next 15 years, the 600 largest cities will account for an estimated 35% of the expansion of the global workforce, according to a new report from the McKinsey Global Institute.  Cities just about everywhere growing in size, GDP, and share of national GDP.  But cities in developing economies are growing at a faster rate.  From the report Urban world: Mapping the economic power of cities:

Today, major urban areas in developed regions are, without doubt, economic giants. Half of global GDP in 2007 came from 380 cities in developed regions, with more than 20 percent of global GDP coming from 190 North American cities alone. The 220 largest cities in developing regions contributed another 10 percent.

But by 2025, one-third of these developed market cities will no longer make the top 600; and one out of every 20 cities in emerging markets is likely to see their rank drop out of the top 600. By 2025, 136 new cities are expected to enter the top 600, all of them from the developing world and overwhelmingly—100 new cities—from China.

Take a look at how the balance of urban power is shifting east:

The lesson for global-minded businesses seems pretty clear.  The action will be where the people are.  And increasingly, the people are going to be in growing cities in emerging markets.  To be sure, there is growth in US cities as well--just not at the same rate.  Read the full report here.

The McKinsey Quarterly has a useful interactive map of the world with city-by-city data drawn from the report.  Click here to explore the map.