Every Monday, the National Bureau of Economic Research, a nonprofit organization made up of some of North America’s most respected economists, releases its latest batch of working papers. The papers aren’t peer-reviewed, so their conclusions are preliminary (and occasionally flat-out wrong). But they offer an early peek into some of the research that will shape economic thinking in the years ahead. Here are a few of this week’s most interesting papers.
Authors: Jessie Handbury, Ilya Rahkovsky, Molly Schnell
What they found: Giving low-income individuals better access to healthy food — fixing the “food desert” problem — would do little to narrow the nutritional gap between rich and poor.
Why it matters: Poor people have poor diets. Many experts blame this nutritional disparity on “food deserts,” low-income areas without access to healthy grocery options. The Agricultural Act of 2014 (also known as the farm bill) will spend $125 million per year improving underserved communities’ access to nutritious food. But this research predicts such efforts will amount to little. Using data on over 200,000 retail establishments, the authors show that the healthfulness of available food varies considerably depending on the socioeconomic characteristics of the community: that richer and better-educated people do buy healthier foods and live in areas with healthier grocery options. When researchers looked at food purchases of over 100,000 households — and controlled for both the concentration of healthy groceries, as well as mobility issues (e.g., not having a car) — they found that better access would narrow the gap between lower- and higher-income people’s consumption of healthy food by only 1 percent to 3 percent, in part because people with lower incomes and less education tend not to buy healthy foods even when they are available. In other words, most of the differences in nutritional consumption by income would persist even if there were no food deserts.
Key quote: “Our results indicate that improving access to healthy foods alone will do little to close the gap in the nutritional quality of grocery purchases across different socioeconomic groups. … Improving the concentration and nutritional quality of stores in the average low-income and low-education neighborhood to match those of the average high-income and high-education neighborhood would only close the gap in nutritional consumption across these groups by 1-3%.”
Data they used: Profile of the grocery purchases made by over 100,000 households from 52 markets across the U.S. between 2006 and 2011. Weekly store-level sales data from Nielsen to identify the products that are available at over 30,000 participating retailers between 2006 and 2011.
Authors: Ann Huff Stevens, Michal Kurlaender, Michel Grosz
What they found: Vocational education at community colleges — that is, programs geared toward a specific skill — can generate large increases in earnings for students, especially for those trained for health occupations.
Why it matters: The fraction of Americans earning a four-year college degree has stagnated, while the demand for skilled workers in specific fields is high and rising. Vocational and technical training at community colleges is thus suggested as a better alternative for some students, as President Obama has acknowledged in making a big push for community colleges. But very little is known about how effective these programs really are. To find out, the authors of this paper examined longitudinal data on students in the California Community Colleges system, the largest public higher-education system in the country, with 2.6 million students. The researchers were able to compare the students’ pre-enrollment earnings with their program of study and post-graduation pay and found that vocational education produced significant returns. On average, students saw a 12 percent to 13 percent boost in earnings. But there was wide variation by program. Health occupations saw huge returns (more than 25 percent in some cases), whereas non-health degrees returned 5 percent to 10 percent.
Key quote: “The extremely large returns to health occupations, and the substantially smaller average returns among non-health occupations merit careful consideration. Health occupations are currently receiving a great deal of attention as promising career pathways for those without four-year college degrees.”
Data they used: Longitudinal administrative data from the California Community Colleges system, which has more than 112 campuses.
Title: “Slack Time and Innovation”
Authors: Ajay Agrawal, Christian Catalini, Avi Goldfarb
What they found: Slack time — such as the policy used at Google, which allows employees to spend 20 percent of their workweek on a project of their choice — encourages innovation, but not, as commonly presumed, because it provides space for creativity and idea generation to flourish. Instead, slack time allows for mundane, task-oriented work to be done, a key ingredient for innovation.
Why it matters: The authors examined the launch of projects on Kickstarter, a crowdfunding website, over five years and used college breaks as a measure of slack time. They linked this school-specific slack time to spikes in the launching (and funding) of Kickstarter projects related to those schools. For example, the timing of technology project launches coincided with engineering schools’ going on break, and artistic projects got started when art schools were off. The authors then demonstrated that new projects tended to spike early in the break as students had time to complete the necessary planning documents that are part of the Kickstarter process. Thus, the authors speculate, this means that innovation was enabled by the availability of time for mundane, execution-oriented tasks, not just time for creative thinking. One barrier to innovation, in other words, is spare time for doing the basic to-dos needed to launch an idea.
Key quote: “Ultimately, our contribution is to highlight the role that mundane, execution-oriented tasks play in the creative endeavor of innovation. Our findings demonstrate that although creativity may be a necessary input for innovation, it is not sufficient. Transforming creative ideas into useful products requires many steps, such as marketing and finance, that themselves necessitate a series of mundane tasks.”
Data they used: Five years of Kickstarter data.