Rationale behaviour creates undesirable results 09-12-2011

It is rational for each Greek to vote for the politician who will give them and their family the best life: 

It is rational for a Greek politician to provide as many benefits as than can to their constituents when the cost of the spending is being borne by someone else - ie the European Union 

It is rational for a european country to lend money at good interest rates to people who will buy their goods - Audi, Mercs etc

In old England workers used to graze common land and they were allowed a certain number of animals. 

So if 20 workers were allowed 10 cows each that meant 200 cows on the common. If one worker added 1 extra cow he could increase his wealth by 10% - and one cow really doesn't matter. 

But every other worker will want the same thing. 20 extra cows means the common is overgrazed and can only sustain 150 cows a year for a number of years - so every body loses 25% of their wealth or three workers lose all their assets...