While the ghosts of the last decade’s housing crisis have (mostly) been put to rest, for many families priced out of their local markets the need for affordable housing remains strong. Like the PC’s infamous “blue screen of death,” the Urban Institute’s map of affordable housing inventory is terrifying to behold. A handful of dark blue swatches in Midwest represent healthy levels of affordable housing inventory. The rest of the country, on the other hand, sits awash in the lightest indigo hues. From barely perceptible azure to the palest cerulean, a majority of states contain less than 50 units per 100 extremely low-income households. More than a third sit at, or close, to zero. As demand for budget-friendly rentals continues to rise, many communities struggle to provide adequate supply. In response to this affordable housing crisis, the White House recently released the Housing Development Toolkit. Part call to action, part policy overhaul, the toolkit’s main purpose it to help cities increase their affordable housing inventory. “The growing severity of unsupplied housing markets is jeopardizing housing affordability for working families,” write the toolkit’s authors, “increasing income inequality by reducing less-skilled workers’ access to high-wage labor markets, and stifling GDP growth by driving labor migration away from the most productive regions,” Accumulated Barriers While New York City’s real estate market is the stuff of legend, until recently most cities were able to supply adequate housing to residents. Unfortunately, several factors have conspired over the last few years to shrink stock and ramp up costs. These “accumulated barriers” are identified by the toolkit as lack of adequate construction, high job growth in areas with low vacancy rates, gentrification, and cost-per-unit increases paired with insufficient public assistance. “The accumulation of these barriers has reduced the ability of many housing markets to...