Over at Marginal Revolution, Alex Tabarrok has this interesting post about how car owners in Boston who free their cars from snow pack after storms gain by their labor limited (in duration) property rights in the parking spaces. A Boston city ordinance allows them to place a lawn chair or garbage can in the space for up to two days, to prevent others parking there, while they are away with their car. Alex also notes that in Washington, DC, where heavy snowfall is more rare, no such ordinance exists, nor has any social norm developed, leaving Washington residents in a quandary about how they might lawfully prevent others from free-riding on their labor. A savvy commentator on Alex's post notes that Chicago does not have any ordinance similar to Boston's, but a workable social norm has developed: if someone else takes the space you recently cleared, their car will wind be damaged.
The title of Alex's post suggests that these property rules are explicable under John Locke's labor theory of property acquisition the Boston ordinance, which seems obviously true at first blush. Locke's theory holds that property is acquired in resources by the act of mixing one's labor with the thing to be appropriated. However, Locke added a somewhat less famous proviso to that rule: there must be as much and as good left for others to appropriate. Given the general scarcity of parking spaces relative to the population of automobiles in just about any major city, it's not so clear that Locke's labor theory of property acquisition would apply. On the other hand, Locke might just say, "Clear your own damn space!"