It's delusional to think we can predict the future, says Scott Adams in a post about US budget forecasting:
For example, can the CBO assume that the U.S. Postal Service shuts down within twenty years? My personal assumption is that by then all letters will be sent by e-mail, and packages will be handled by private companies. It would be insane to keep funding the Post Office twenty years from now. But I doubt the CBO forecasts assume that it goes away...
...Suppose medical technology gets to the point where you can diagnose potential problems, from gene analysis for example, and start treating things before they become expensive? Preventing cancer has to be a lot cheaper than treating it after the fact. How do you forecast a budget for that?
Reinforcing this point, development blogger William Easterly has some neat maps showing the speed at which global mobile phone use has taken off in a decade. Notice the way the dark blue creeps in, indicating over 40 mobile phone subscribers per 100 people. Who would have predicted it, and even if someone did, who would have believed it?:
2001
2004
2008
