Paul Ehrlich’s warnings about a population bomb never really took hold, but America and the rest of the world has lived with an expectation that the human species will continue to grow.  In the next several decades, there’s every indication that, here in America, and elsewhere in the world, that will not be the case.  And while our guest urban policy expert Allan Mallach, author of “Smaller Cities in a Shrinking World: Learning to Thrive Without Growth,” lays out the various reasons that the global population, in general, is on a downward population trajectory, he then zeroes in on cities of a certain size here and abroad and the implications of that reality, which even ‘pro-naturalist’ policies will not be able to reverse.  And given that we have always equated population growth with economic growth, he tries to adjust our thinking to suggest that there are new possibilities in something he called ‘networked localism’ to change that thinking and decouple those assumptions.  He makes a compelling case for where cities are headed in the period ahead and the adjustments that will be required to thrive with fewer residents.