Free market vs high income While answering this question I was doing some research and found that 



the high-income world has Free Markets.

Is it that because they are high-income, they have free markets, Or, is it that their free market made them high-income?

A supplementary question is: if the latter is true, why don't all low-income countries adopt Free Markets?
Capitalism works best when there is elasticity- the price can go up or down by a marginal unit without running into the problem of plateauing supply or demand.

In extremely wealthy or extremely poor places, the market can experience inelasticity- where a change in the price will not affect demand.

Cheap item inelasticity:
E.g. The water is free at restaurants but we don't see people drinking insane quantities of water, though supply/$0 should equal infinite demand.

Expensive item inelasticity:
Someone is stranded in the desert and has no water. A vending machine offers him water for 100 gold coins. Even though the price is very high, the man still needs water. To save his life, the man would pay 100 or even 200 coins, doubling the price without reducing the demand. As it happens, the man has only one coin and dies because the vending machine was unable to adjust its price to make a sale.

Cheap item inelasticity is rarely a problem because if a country is stuck with undesirable surplus, it could just burn it or throw it in the sea.

Expensive item inelasticity is more prevalent in poorer places where more of the population is unable to afford important goods. A country could A) allow its people to starve B) subsidize goods for the poor C) set a maximum price for the item.

B and C are not free-market options.

A poorer economy is more likely to run into the problem of Expensive Item Inelasticity and is thus more likely to attempt to resolve it.