This is a guest post by Aaron Newton, who is working with coauthor Sharon Astyk on the forthcoming book, A Nation of Farmers. Aaron contributes at Groovy Green; he also blogs at Powering Down. Aaron is a land planner and garden farmer in suburban North Carolina, seeking ways to transform the current course of human land use development in an effort to prepare for the effects of global oil production peak and its outcome on automotive suburban America.

The notion of our standard work week here in America has remained largely the same since 1938. That was the year the Fair Labor Standards Act was passed, standardizing the eight hour work day and the 40 hour work week. Each Monday, Tuesday, Wednesday, Thursday and Friday workers all over the country wake up, get dressed, eat breakfast and go to work. But the notion that the majority of the workforce should keep these hours is based on nothing more than an idea put forth but the Federal government almost 70 years ago. To be sure it was an improvement in the lives of many Americans who were at the time forced to work 10+ hours a day, sometimes 6 days of the week. So a 40 hour work week was seen as an upgrade in the lives of many of U.S. citizens. 8 is a nice round number; one third of each 24 hour day. In theory it leaves 8 hours for sleep and 8 hours for other activities like eating, bathing, raising children and enjoying life. But the notion that we should work for 5 of these days in a row before taking 2 for ourselves is, as best I can tell, rather arbitrary.

The idea of a shorter work week is not a new one to anyone old enough to have lived through the energy shocks of the 1970's. It should be fairly obvious to anyone interested in conserving oil that reducing the number of daily commutes per week would reduce the overall demand for oil. There are about 133 million workers in America. Around 80% of them get to work by driving alone in a car. The average commute covers about 16 miles each way.

So let's stop and do some math...and I'll try to argue for 16 reasons why a four day work week is a good idea.

Also known as Name Those Wiggles!!?. See discussion below for some ideas.

Estimate of US deployed gasoline fuel economy by month, Jan 1990-Mar 2006, with 12 month trailing average and linear trend. Graph is not zero-scaled. Click to enlarge. Source: FHWA for VMT stats, EIA for gasoline supplied, and Transportation Energy Data Book for diesel vehicle correction. See text for details.

The Federal Highway Administration is out with January Travel Trends, giving details of how many vehicle miles were traveled in that month. After being flat pretty much all last year, January 2006 was up 3.8% compared to January of last year. The increase affected all regions, and both rural and urban roads to varying degrees, so there's little doubt that it's a real effect (though it was aided slightly by the fact that January 2005 had somewhat depressed VMT).

Monthly US vehicle miles traveled for the last three years. Source FHWA

Stuart and I have been emailing back and forth regarding his post on modeling state gsp using vmt as an independent variable.

Paula, both here and on her blog, correctly suggested that education should also be considered as an independent variable. So, what I did was pull together some data on % college educated for each state and include it in with the data Stuart had already collected...and then I conducted a multivariate regression on the data, which is presented below.  That regression allows us to find out what the effects are for all of these independent variables on gsp/cap after controlling for the effects of the other variables.  This allows to get a better picture of what's going on (though we lose the visual facility that Stuart had with his bivariate graphs).  Much more under the fold.

So, what's the takeaway?  Stuart's right: states with higher vmts have lower gsp/cap, even after controlling for education and population density.