Edward Glaeser wrote that urban farms are a bad idea (Boston Globe
editorial 6/16/11). I used to run a suburban farm and I have a few
ideas about that. I also have a degree in real estate economics and
like to contemplate land values and urban form.
Glaeser makes a blanket statement that urban farms are a bad idea
because they will lead to increased carbon emissions from driving. His
argument is that taking land in urban areas and using it for farming
will correspond to decreased (home and business) densities in urban
areas. There is evidence that reduced densities translate into higher
automobile emissions from longer average trips.
I generally enjoy his advocacy of environmentally preferable urban
form, but I wonder what is his beef with agriculture? It’s not like
urban farms are out to get us! One clue of his concern is dropped at the very end of the piece, where
he urges Michelle Obama to advocate for hi-rise apartments rather than
I agree with him that the environmental benefits of urban farms, as
described as “reduced food miles” is a specious argument in their
support. Moving food from the country to the city is a small portion
of the energy used in food. Much more food is wasted, their carbon in
vain, than what is used to bring it into cities. Carbon reduction in
the ag sector is mostly about soil organic matter and fertilizer use.
That’s a whole ‘nother issue.
The idea that farms would de-densify an area is explained in a vacuum.
In the real world, density is a function of competing economic forces: zoning regulations
distorting the market which is influenced by people’s average
willingness to travel, various natural and infrastructure features,
and competing uses. To imply that arriving, de-densifying farms would
not influence a corresponding densification nearby is wrong. Ceteris
paribus, (all things being equal) if someone buys urban land to farm
it, any alternate use does not specifically re-locate somewhere
further “outside” the city (however you want to define that) but
rather relocates to the next available opportunity on the market. Of
course that’s often farmland in the hinterland, but could just as well
be some other vacant lot or adaptive re-use site in a city.
I believe the market for land is the big issue related to urban
farming and whether it is going to happen or not. I mean, the reason
suburbanization and the expansion of cities into agricultural land
occurs is farmers selling to developers. It’s somewhat odd that Glaeser
doesn’t mention markets at all. Possibly, he is coming from a
perspective of caution to public policy makers, and in this sense is
supporting the case to not let politicians distort markets and push
farming onto urban lots. There could be better uses for various sites
in the city other than supposedly reducing truck emissions.
Urban farming’s best return on investment is education for people, not
just kids, to know about the food system and the basics of
agriculture. It also could mean jobs, it could mean historic
preservation, it could mean improved nutrition. I don’t think it will
mean high return on investment for a lot of people. Land values will
always push farming to the side so a more lucrative activity can take
place. Like a high-rise apartment building.
A similar argument was made by Sarah Laskow at Grist