In Christianity, the ultimate future for the world is a renewed creation with new heavens and new earth. In that new creation there will be no economists.
Isaiah 55 presents one of the most picturesque descriptions of the new creation, and the first verse invites the reader to “buy milk without money and without price.” With this sentence, the economy is has gotten one item smaller.
Since economics is the study of scarce resources which have alternative uses, there is no need for it where there is no scarcity. Economics does not have much to say about the allocation of sunlight or air (in most case) since these are so naturally plentiful that everyone can use as much as he or she wants without depleting the total amount by any great amount. They are non-economic goods.
Most goods are scarce, however, and their relative scarcity and market value are represented by prices. Prices simply convey information about who wants what goods and what they are willing to give up to get them. In a monetary economy these prices are given in terms of money.
Isaiah says that milk will simply have no price and can be bought without money, which indicates that it is a non-economic good in the new creation. Milk will be as ubiquitous as air or sunlight; it will no longer be scarce.
Milk is not the only thing that is overflowing in Isaiah’s vision. The chapter goes on to conclude saying “instead of the thorn shall come up the cypress. Instead of the brier shall come up the cedar tree…” This passage harkens back to Genesis 3 in which human sin results in the earth being cursed so that the ground brings forth thorns and briers and must be worked to produce useful plants. Since the earth stopped bringing forth abundant produce, there was scarcity. Adam couldn’t grab fruits and vegetables left and right anymore; he had to work for them. But in the Isaianic vision, that curse will be finally undone and the new earth will no longer produce thorns and briers but myrtle and cedar. When creation is put back on track it will once again produce abundance on its own; there won’t be scarcity anymore.
And there is the end of economics. Since scarcity will become a thing of the past in the finished new creation, all goods will be non-economic goods. Economists will be out of a job, but not to worry; the milk there is free.