A metric of success that planners and other local officials can use to ask this question is value per acre. This is a measurement of the productivity of a land-use pattern, much in the same way that yield per acre is the measure of the productivity of a farm field. How much wealth is created on each acre of developed land? It’s simple to compute and powerfully correlated with success. Yet few cities consistently incorporate this metric into their land-use analysis.
When modern cities are analyzed by this measure, pre-Depression neighborhoods —even those that are far from affluent—financially outperform even the newest stuff being built today. Collections of blighted homes and underperforming commercial stock are routinely found to provide a greater return on the public’s investment than anything built in the past couple of decades. Acre by acre, they produce more concentrated wealth and consume less public infrastructure and services. It might shock most people to learn that in many American cities, the poorest neighborhoods subsidize the wealthiest.The explanation has much to do with the pattern of development we adopted in the mid-20th century. We began to build in a manner oriented toward cars, not people on foot. All the acres needed for traffic flow, buffering, and parking are wasted, non-performing space. They cost us a lot of money, yet yield a pitifully low ROI.