Economics vs physics vs evolutionary psychology
The main uses of the University intranet when I was a student back in the early 90s were email, message boards, porn (obviously), MUDs, sharing academic ideas and multi-user tank fighting games. With the exception of the porn, all of these uses were 'many to many' interactions - although the population was much smaller than it is now. In fact, the intranet was just a loose, simplified model of normal student life. Little has changed; Web 2.0 is largely the same as various aspects of real-world life, only the population pool is bigger and it is much easier to search through to find people like you. Web 2.0 is basically a social search engine.
So, what about the economics? Game theory has played a major part in the social sciences for a few decades now (as economists know full well!), but I suppose most readers of The Register aren't familiar with sociology. Really, Becker's motivation is not in introducing new ideas per se - he is actually fighting a turf war with the physicists and the geneticists over the quickly sciencifying (is that a real word?) field of sociology.
Read a selection of pop-sociology books and you will quickly spot three camps. The Economists are now telling us that the mathematics used to explain human interactions aren't mathematical theories, they're economic theories. TIn the second camp, the physicists will show how fluid dynamics can be used to model road traffic and how phase transitions may model social change, and will explain that if economists did proper empirical testing, then they would see that human behaviour doesn't obey current economic models anyway.
The third camp, the current new kids on the block, are the Evolutionary Psychologists> They will tell you that it is an over-simplification to treat humans as the simple 'atomic' interacting units. Both the economists and the physicists fail to grasp that the real 'rational' agents are not humans, but are in fact our genes, acting out through our predisposed behaviour patterns. Humans don't automatically behave selfishly - our genes do (and by this I mean that genes are succesfull if they aid the spread of themselves - selfish in this sense is not the same as selfish in an everyday sense. Read 'The Selfish Gene' by Richard Dawkins for a better explanation!). Altruism is no mystery once we realise that an act of altruism doesn't have to directly benefit the individual in question for there to be a beneficial outcome of owning the genes that lead to occasional acts of altruism. As long as the gene that makes us altruistic also halps make us successful in some other way, it will spread. Yes, human behaviour follows mathematically determined efficiency - but that is because evolution follows mathematical rules.
Of course, non of these disciplines allow true free will as many a layperson would like to imagine they are in possesion of. This is not a big disaster though - the importance of self-determination is a recent phenomenon, largely created by the political philosophers of the last couple of hundred years and is mostly focused on the politically and socially liberal consumer society of the present day. For thousands of years many humans believed that they were a part of a Divine plan, that their sins were the result of Satan's influence and that their lives were ultimately at the mercy of forces beyond their individual control. Even now, millions think that their futures are predestined, and so use horoscopes and Tarot cards to predict what is going to happen in the future. Others happily believe that their behaviour is profoundly influenced by 'energy fields' that obey laws similar to those found in physics.
Having complete control over one's behaviour is not a traditional human belief. Accepting that humans do not have the ability to make geniunely free concious choices (call it Divine plan or mathematical equation, the two are equivalent in this context) is an old trick - and perhaps one we would be better off re-learning. It would certainly help us understand how the big companies, politicians and religions manipulate our behaviour for their own benefit!