What City Observatory did this week

1.  How great cities enable you to live longer. We take a close look at some findings from the Equality of Opportunity Project on the connections between community characteristics and life expectancy. It turns out that among people in the lowest income quartile, some of the strongest correlations with longer living are aspects of the community, including population density, the share of immigrants in the population, and regional educational attainment. We know that cities promote higher levels of innovation and productivity, and that city economic success is correlated with education, but these data suggest that there may be important spillover benefits in terms of life expectancy even for those who are relatively low income.

2. Your college degree has a higher payoff if you live in a city. We all know by now that education is strongly correlated with income: those with more education, on average, earn more than those with less. There’s also a marked geography to the economic returns to education. If you really want to capitalize on your college degree, you’re much better off living in a city.  Those with a BA or graduate degree earn 25 to 35% more if they live in an urban area than a rural one. In contrast, those with just a high school degree earn only slightly more in cities than rural areas. This urban wage premium is likely a key reason that well-educated workers are increasingly concentrated in cities.

Must read

1. School attendance boundaries and segregation. Seven decades after Brown v. Board of Education, American schools remain highly segregated by race. Part of this has to do with residential segregation, but in many cities, school segregation is actually intensified by the way attendance boundaries are drawn. Want to get really smart about how school attendance boundaries can either offset or worsen racial segregation? Have a look at Vox’s illustrated explainer of this important subject. It’s a great mix of accessible explanation of a lot of pretty dense academic literature combined with a drill-down data tool that let’s you see how school’s in your city perform on these metrics. Vox’s Alvin Chang deserves a public policy Golden Globe award (if there were such things) for his work here: the web-page generates customized local maps and performance charts on the fly.

2. A radical proposal to reform zoning in California. Fresh on the heels of last year’s legislation to liberalize zoning in the Golden State, State Senator Scott Wiener has proposed an even more sweeping proposal to allow much higher densities in areas with good transit service. SB 827 would mandate within a half  mile of high capacity transit service (like San Francisco’s BART stations) and within a quarter mile of frequent transit stops that local governments eliminate density maximums (such as single family home zoning), and minimum parking requirements and have height limits no lower than 45 to 85 feet. This proposal would open up vast swaths of transit served urban sites to much more intensive development, and could dramatically expand the supply of housing and ease California’s chronic housing affordability problems. It is, of course, a major challenge to the traditionally local prerogative of setting densities. We look forward to the debate that this proposal will generate in California.

3. A new traffic safety paradigm. Todd Litman of the Victoria Transportation Institute has once again done masterful and methodical job of dissecting a major tansportation policy issue.  This time, its traffic safety. Presenting a range of time series and cross sectional data, he illustrates how US traffic death rates, which had been declining, have ticked upwards in recent years. Death rates to traffic crashes are much higher in the US that in other countries, and also vary tremendously by state. A key risk factor that’s generally understated in US discussions–if not omitted altogether–is the much longer distances Americans drive. As Litman points out, this means that measures to reduce driving improve safety: “extensive research indicates that policies which increase vehicle travel, such as automobile-oriented transport planning, lower fuel prices,and sprawled development patterns tend to increase traffic casualty rates, and those that reduce vehicle travel, such as multimodal transport planning, public transit improvements, higher fuel prices and road user fees, and Smart Growth development patterns, tend to increase traffic safety.”

New knowledge

How much is urban land worth? One of the biggest assets in the economy is the value of land in the nation’s cities. Valuing it correctly actually turns out to be difficult because in most transactions, land comes bundled with improvements and buildings. A new paper by three economists, led by David Albouy of the University of Illinois uses data on land sales in a number of cities, coupled with a probabilistic estimating function to calculate the total value of land in metro areas; the study also sheds light on the pattern of variation of land prices within metro areas. Bottom line: the value of urban land in US metro areas is something on the order of $20 trillion, roughly 1.3 times the value of annual GDP. Nearly half of that value is in the nation’s five largest conurbations (list).  The paper also looks at the land price gradient–the degree to which land decreases in value the further it is from the center of an urban area.  In large cities, the gradient is particularly steep; urban land in the center of New York is worth 22 times what it is ten miles away.  Other metros tend to follow a similar pattern, although the differentials between core and periphery are smaller, averaging about 6 times higher in the center compared to ten miles out..  The report has a number of other interesting observations:  the average value of an acre of urban land is about $370,000; that value peaked in 2006 and fell through 2010 (the latest year in the analysis). More than a third of the value of urban land is in public hands (in the form of roads, parks, and other public landholdings.