Tuesday, October 12, 2010

Economist's Notebook: The Economics of Moles

[I resisted the temptation to call it Mole-o-nomics, aren't you all proud of me?]

This summer a mole (I shall henceforth call him Morris, though in truth I know not its name nor gender) decided to make himself at home in my back yard.   At first I was okay with this development, feeling I could live in harmony with my subterranean little friend.  And at first, this symbiotic arrangement seemed to be working out just fine - a couple of mole mounds appeared, but only one in the grass and I tended to all of them easily.  But then old Morris started to expand his home at the expense of my yard that I had only just completely rehabilitated.  Not really being a good guest this Morris, thought I. And recently he has really gone into overdrive digging up my yard and making a general mess of my lawn.

So what to do?  Well. I went down to the local hardware store to look for mole traps but I quickly began to have serious misgivings as I looked at the description of the violence promised to Morris.  These traps are also difficult to set (requiring lots of digging and careful placement) in addition to their being quite horrific.  Inflicting such horrors on poor old Morris seemed to be cosmically quesitonable, after all Morris is simply being a mole.

But then the good salesperson introduced me to the 'sonic spike.'  This is a device that sends out sonic waves in the ground and claims that this will drive away moles.  My first instinct is that this type of application of technology never works and a quick check of the intertubes reveals less than satisfied customers.  Nevertheless, the manager of the hardware store was claimed to have personally used them successfully in my neighborhood so I figured it was worth a try.

Besides, this approach has economics on its side.   What I mean by this is that the principle of the sonic spike is to make life in my yard not unbearable but marginally less pleasant than other places.  In economics we know that economic decisions are made at the margin.  In other words, Morris doesn't think 'well the benefits of Emerson's yard outweigh the costs even with this annoying noise (which is probably true), so I'll stay.'  No, Morris, being subject to the same incentives that influence us superterranean beings, thinks 'hmmm...here are two yards seperated only by a fence, but one is just slightly more annoying so I think I'll go to the more peaceful one.'  So, assuming I am right about the response of moles to incentives, it'll work.  But even if it doesn't, it makes for a good economics experiment.

Now, you have by now seen the er...moral ambiguity associated with this plan.  My mole strategy has an external cost that will be born by my neighbors: I am not removing the mole, only hoping to get it to move next door.  This is an example of a classic externality problem: if a the total cost of an activitiy is not born by the actor, too much will be done.  I am a good self-interested rational agent, and since I don't have to pay the cost of my neighbors' mole problem, I do not figure it into my calculation of relevant costs and benefits, so I choose the spike.

However, a bigger problem arises if all the neighbors decide on the same mole strategy.  If we all plant sonic spikes, the old Morris will think that every yard is as good as the next and whatever made him choose mine will cause him to chose it again. 

So I am not convinced it is the solution to my problem (and there is the downside of little high-pitched hums that eminate from the spike about every 30 seconds), but it'll be interesting if it is, at least for now.  And it keeps me karmically safe in the interim.

Failing that I may go with what seems the next best route: stick a hose from the tailpipe of my car into the ground and gas old Morris to death.  My big quesiton here is how do you get the car to not stall out due to clogging the tailpipe - isn't this similar to the old banana in the tailpipe trick?


Rudy said...

When I had a mole in my backyard, I found a nice, new tunnel, stuck a garden hose in it, and turned the water on full blast. Eventually he poked his little head up from the mud. I whacked him with a shovel (the literal "whack-a-mole" game).

The next summer, his brother moved in. That was three years ago. We have learned to live with a chewed-up back yard.

Dann Cutter said...

Get a cat.

Your kid(s) (not sure on the quantity there) will love it, it will deal with both the current mole, and new moles and various other critters, and it buries its poop.

Morris also provides a marginal good to the cat. And frankly, possibly a paper, given the likely interval of reoccurrence, argues against the long term law of diminishing marginal utility for the cat. And continues to save you buying as much food, which is a savings to you.

(I'm obviously in week 3 of Econ 311). And like cats.

Patrick Emerson said...

A cat, really? Are they dependable mole hunters?

Dann Cutter said...

In my experience and the others I know with both a mole issue and cats, (so an N of 4), yes - if allowed outside. A petdoor is nice, but see below...

It, however, will be a wash Kharma-wise unfortunately; as though purposeful, the mole will be played with, killed, and in my experience eaten all but enough to make your wife holler at you to go get rid of it when the cat leaves the carcass on the front step (or worse, the kitchen floor).

In our case, my wife now insists I check the cat's mouth before letting it in for the night, which often requires a trip out in the coastal rain - then again, in fairness to her, the cat has chosen that her side of the bed is the place it will drop the day's kill in hopes of reward.

There are definitely some 'bads' associated with cat ownership. But, as that pet owners tend to live longer, marginal good of ownership should readily outweigh those negatives.

Patrick Emerson said...

Karmically, I feel fine with the cat solution. A cat is being a cat, after all. We are now into week two with the spike and it is supposed to take 7 to 14 days. No new apparent mole activity this morning...