The main theme of this book is that the urban population of the world for the first time is more plentiful than that of rural areas (page 1). Cities will also account for most of the future global population growth (page 2), and the growth of the new cities in the developing countries will outpace that of Victorian England (page 3).
Housing in these new cities is problematic. What the author calls the "formal home market" does not provide enough housing to meet the need, and the government in many countries provides very little housing aid (page 67). In part, this is because the middle class and rich evade taxes, so there is a minimal tax base to support building public housing. In addition, the IMF and World Bank do not advocate the taxing of wealth, "conspicuous consumption," or real estate (page 68) to pay for public housing, thereby perpetuating inequality. In addition, the author writes that the Structural Adjustment Programs (SAPs) of the World Bank and IMF force developing countries to spend money on servicing their debt rather than on providing services to the poor.
In response to the need for massive new housing, what the author calls "megaslums" have developed in the developing world to house millions of people. These slums are a response the inability of the poor to find housing that is near their jobs, safe, and affordable. For example, some people prefer to live near a train station or produce market to get to work, even if they don't have a roof over their heads (page 27). The author states that this type of "rational-choice" model applies to the slums in most cities (page 29). For example, in Cairo, families can choose to rent an apartment, if they can find one; to squat in an illegal dwelling such as a rooftop from which they might be evicted; to squat on public land; or to buy a plot in a space without legal building permits.
The author also writes that the new poor constitute an "informal working class" of about one billion people (page 178). Jobs in the informal sector of the economy are growing more quickly than jobs in the formal sector. As he writes, the new poor are as "homeless in the contemporary international economy" (page 178) as they are homeless in their cities. There aren't enough formal jobs, which come with greater rights and bargaining power, to lift slum dwellers out of poverty. Instead, they are forced into positions such as prostitution and selling their organs to survive. At this rate, the author predicts the future of urban slums will be dire.