From New Geography, we hear a lot of talk these days about so-called “global cities” — but what is a global city? Nick Holdstock interviews Saskia Sassen, author of Cities in a World Economy. The creative class to the rescue of cities? Denis Eckert, Michel Grossetti and Helene Martin-Brelot on how developing education and infrastructures that can serve the population as a whole may be a much more productive strategy. Robert J. Sampson reviews The Great Inversion and the Future of the American City by Alan Ehrenhalt. Can cities be "resilient" and "sustainable" at the same time? The urban areas of the next 100 years will have to be both — but that’s tricky. David Madden reviews The Transatlantic Collapse of Urban Renewal: Postwar Urbanism from New York to Berlin by Christopher Klemek. Whither urban studies? Andy Merrifield wonders. The new ruralism: Paula Cocozza on how the pastoral idyll is taking over our cities. Strange, beautiful and unexpected: Betsy Mason on planned cities seen from space. Can architects create a new neighborhood of skyscrapers in New York? Dave Schilling on why gentrification is only bad if you’re poor.