The simplest explanation of this theorem is that "under the premise of high transaction cost, rights should be given to those who cherish rights the most and can create the greatest benefits;" And blame the responsibility on those who can avoid it at the least cost. "Posner theorem actually tells people a truth: true fairness should be based on efficiency.

Try to illustrate Posner's point of view with weather forecast. Posner believes that although the weather forecast is open, it can not get direct compensation from consumers by selling this "commodity", but can indirectly compensate by buying and selling futures contracts and making profits from the "futures" market. It is assumed that the publisher of the weather forecast can fully foresee the deterioration of the future weather. Therefore, you can go to the futures market and buy a lot of future agricultural products at the current price; At the time of product harvest, the distributor sells agricultural products at the high price at that time (that is, at the time of future delivery) and obtains high profits from them. In this way, the private property owners of information goods can completely overcome the economic externalities of public goods through "tortuous" charges, so that the operation of the private market system can avoid the trap of "market failure".