The trouble with central planning

Procter & Gamble...noticed an odd thing about Pampers, its well-known brand of disposable nappies: although the number of babies and the demand for nappies remained relatively stable, orders for Pampers fluctuated dramatically. This was because information about consumer demand can become increasingly distorted as it moves along the supply chain. For instance, a retailer may see a slight increase in demand for nappies, so he orders more from a wholesaler. The wholesaler then boosts his own sales forecast, causing the manufacturer to scale up production. But when the increase in demand turns out to have been only a blip, the supply chain is left with too much stock and orders are cut back.

It's even harder for Communists.