Bertrand Russell’S Chicken (And Why It Was Non An Economist)

When that pioneering economist David Hume wrote close the problem of induction, he talked close the possibility that the Sun would non rising ane morning. There is no agency nosotros tin know ‘for sure’ that it volition rise. (In contrast, nosotros know for certain that 1+1=2.) Just because the theories nosotros select advise it volition rising each morning, as well as those theories select been correct so far, does naught to ensure they volition hold to hold out right.

The work amongst this event is that it is really hard to imagine the Sun non rising every morning. Bertrand Russell had maybe a improve example. The chicken that is fed past times the farmer each morning time may good select a theory that it volition ever hold out fed each morning time - it becomes a ‘law’. And it plant every day, until the twenty-four lx minutes menstruum the chicken is instead slaughtered.

When I used to lecture close economical methodology, I liked to nation that this chicken was non an economist. Now you lot mightiness nation that no chicken is an economist, but suppose that chickens were equally intelligent equally the farmer who keeps them, so they could hold out an economist. Economics is at a disadvantage compared to the physical sciences because nosotros cannot create so many types of experiments (although nosotros are doing to a greater extent than as well as more), but nosotros select unopen to other rootage of evidence: introspection. So if Bertrand Russell’s chicken had been an economist, they would non only select observed that every morning time the farmer brought them food, as well as hence concluded that this must tumble out forever. Instead they would select asked a crucial additional question: why is the farmer doing this? What is inward it for him? If I was the farmer, why would I create this? And of course of written report trying to response that inquiry mightiness select led them to the unfortunate truth.

I idea of this when reading through the fascinating comments on my ship service on rational expectations, as well as posts others had written inward response. You tin run across why the habit of introspection would brand economists predisposed to assume rationality generally, as well as rational expectations inward particular. (I intend it likewise helps explicate economists’ aversion to paternalism.) It exclusively plant to move your ain idea processes equally a guide to how people inward full general mightiness behave, if you lot intend other people are essentially similar yourself. So if your ain thoughts atomic number 82 you lot to postulate unopen to theory close how the economic scheme behaves, as well as so others similar to yourself mightiness hold out able to create something similar the same thing.

 

But of course of written report this occupation of reasoning could likewise hold out misleading. An economist who introspects does so amongst the assist of the economical theory they already have, so their introspection is non representative. H5N1 psychologist or behavioural economist mightiness come upwards to really dissimilar conclusions from introspection - what biases create I convey to this problem, they may ask. Economists may likewise hold out fooled into thinking their introspection is representative, because they are surrounded past times other economists. So this conjecture close introspection does niggling to present that assuming agents select rational expectations is correct (or wrong), but it may hold out ane argue why most economists divulge the concept of rational expectations so attractive.