The new face of the possible

Warning: this is a change from our usual programming. If you are not interested in the theory of interacting systems, you might want to skip it.

One of the things that has really changed with the widespread use of computer models is the achievability of perfection. What do I mean? Well, one big difference between a computer model and reality is the ability to restore state. That is, to make the world just like it was earlier. The undo button. You really can, in a model (and by `model' I include programs like Word or Excel, computer games, and so on as well as more obviously model-like things) undo the result of some action as soon as it goes wrong. That is much much harder in the physical world, as anyone who cooks or does DIY will affirm. What this changes is the how hard it is to do some difficult things.

Suppose you have a 1 in 1000 chance of getting something right. What that thing is doesn't matter - think of making the perfect Bearnaise, or building a shed, or jumping just right so that Lara Croft navigates over a chasm. In the real world, it may take many many tries before you get it right. The amount of time required is considerable. In a computer model, though, if you save frequently, you can just restore from the last good point. So if that 1 in 1000 is the result of three separate 1 in 10 actions, then you can treat each separately. As soon as you get one of them right, you never have to do it again, as you can restore the state just after you succeeded. This dramatically changes the amount of time needed to do difficult tasks that rely on a sequence of smaller but still hard-to-do things. (It changes the hardness in particular from multiplicative time in the number of steps to additive time - as any complexity theorist will tell you, that is huge.) At least in a virtual world, perfection really is sometimes possible.

Office decorations

Note to CEOs everywhere. No one, not your shareholders, not your staff, not your clients, thinks you deserve a $87,000 rug. Buying one shows a spectacular failure of judgment. Buy something cheap and inoffensive instead. But don't go too far.

Update. Thain is paying the $1.2M back, according to a letter leaked to FT Alphaville. Good on him.

Your real estate data point of the day

One of the points I have repeatedly mentioned is that it did not take a very large fall in house prices to create the credit crunch. Contagion and widespread bank stress had begun by early 2007 despite falls at that point of only 10% or so nationwide. But of course the falls in the worst affected areas - including Florida, Nevada, and California - were rather worse. And since 2007, as Bloomberg points out, things have got quite a lot worse. In particular rising volumes of foreclosures are driving steep price falls:

A total of 19,926 new and existing houses and condos sold last month in Los Angeles, Riverside, San Diego, Ventura, San Bernardino and Orange counties, up from 13,240 a year earlier... The median home price in the region fell 35 percent to $278,000...

Foreclosed homes accounted for 56 percent of Southern California’s December sales, more than double the amount a year earlier, MDA DataQuick said.

Such transactions made up almost 70 percent of sales in Riverside County, where the median price plummeted 41 percent to $209,000. Sales jumped 77 percent to 4,435, MDA DataQuick said.

Really...

I leave you lot for a week in Asia, and when I come back, the banking system is broken, RBS has announced the largest UK corporate loss ever, BofA has taken another $20B of TARP money and a $100B asset guarantee, and Ireland has nationalised Anglo Irish Bank. I can't leave you alone for a moment can I?

Country Systems

Which systems work well in a town tells you a lot about the place. The title of this blog was inspired by the wonder of the Italian coffee system, something that provides good, cheap coffee everywhere. In France, it's the trains. They just work. Similarly the New York taxi model - cheap, available, often don't know where they are going - is much better than the London one - expensive, disappear after 11 or in the rain, and do know where they are going (but will take you the long way anyway). That's insightful.

In Cambodia, the tuk tuks are very effective, much like New York taxis. Water is on sale everywhere, reflecting a hot country with a lot of tourists from cooler places doing more exercise than they are used to. (Have you seen how steep those temple steps are?) And petrol is sold in glass bottles, every few hundred yards. You never have to worry about your tuk tuk making it to a petrol station, as the petrol vendor is always within walking distance.

This make me wonder about a variant of google maps where instead of plotting where xs are, they plot the average density of xs. Or even the difference between the density here and the average density in place of comparable population density. This isn't quite a sharp idea, yet, but with a bit of luck you can see roughly what I'm getting at. It would be a kind of 'what's different about here' plot.