illuminating science

Well, I’ve spent the last couple of weekends (and then some…) moving house. And while I’d love to say that this was a relaxing process, there’s not much chance of that. First of all, I had to find a place - I’m renting, with my partner Jenny, and January is the busiest time of the year for rentals in Australia, so a property generally is only on the market for 24-48 hours if it’s half decent (i.e., they have an inspection, and are surprised if they don’t get two applications within a couple of hours!) So it’s a pretty cut throat business.

But I realised that I can use maths to get the best results: my situation was actually a perfect setup for the application of the “37% rule”. To recap: I’m trying to find the best place to live. But I don’t know how good the places on the market can be (taking into account size, location, price, facilities, etc), and if I don’t apply for a place immediately, I’ll probably miss it. So I have to see a property, and decide to either take it, or lose it forever and hold out for something better. Now, the more I pass up, the better sample I have of properties (and the better I’m able to say how “good” a place is) but I run the risk of missing the “perfect” home. Plus, I’m on a deadline (I had to move within 2 weeks, when my old lease expired.)

So what should I do? It turns out, to maximise my chance of getting the best place, I should sample 37%, or roughly one third, of the properties I expect to see. So, if I’m looking for 2 weeks, I might expect to find 20 “suitable” properties, satisfying my basic requirements of location and so forth. I should then look at seven of them with no intention of taking them, but noting which is the best. After that, I take the next property which is better than the best I’ve seen so far (from that first seven, or others I’ve seen since) - this gives me the highest chance of getting the best property. Of course, it’s entirely possible that the best property was one of the first seven, and I’ll have already passed it up - then I’ll be stuck with the 20th house, whatever it may be - but this scheme is the best compromise. Other variations exist which try to ensure that I won’t get the worst property, but have a lower chance of getting the best (by looking at fewer houses (say, 5) in that first sample), or where I’m willing to take any of the top three houses.

You’d be amazed, though, at how many situations this theory applies to. What if you’re walking down the restaurant strip, trying to find a place to eat? If you don’t want to go back, simply check out the first 37 percent of the restaurants, then keep walking till you find the next best one. Some people have also applied it to the dating game! Estimate how many people you’re likely to date in your life, dump the first 37% but keep a photo of your favourite on your bedside table. Then, marry the first one after that who beats your sweetheart! Of course, every rule has exceptions and sometimes you get an offer that’s too good to refuse, 37% or not. Sometimes, mathematics doesn’t have all the answers!

In the end, I didn’t exactly follow the 37% rule, but I did sample places and reject them, even though they were “adequate”, in the hope of finding somewhere better. Which at the end of the day, I suppose, is fairly common sense! I’ve got to get back to work for now (I’m giving a conference talk in a couple of weeks!) but I’ll relay the upshot of all this, and the trials of furniture moving soon. Cheers!