With some models of money and a representative-agent there is no reason for monetary trade because identical individuals can consume their own production. Lucas proposed a parable involving differentiated products in a cash-in-advance model to avoid this problem. This paper studies Lucas?s...

More advanced technologies demand higher degrees of specialization - and longer chains of production connecting raw inputs to final outputs. Longer production chains are subject to a "weakest link" effect: they are more fragile and more prone to failure. Optimal chain length is determined by the...