Which tools allow economists to determine if the allocation of resources determined by free markets is desirable?Group of answer choicesThe equilibrium price and quantityIncomes of and prices paid by buyersProfits and costs to firmsConsumer and producer surplus

Economists use several tools to determine if the allocation of resources determined by free markets is desirable. Here's how each tool mentioned in your question works:

1. The equilibrium price and quantity: This is the point where supply and demand intersect in a market. If the market is at equilibrium, it suggests that resources are being allocated efficiently, as the quantity supplied matches the quantity demanded.

2. Incomes of and prices paid by buyers: By analyzing the incomes of buyers and the prices they pay for goods and services, economists can determine if resources are being allocated in a way that is fair and beneficial to consumers.

3. Profits and costs to firms: By looking at a firm's profits and costs, economists can assess whether resources are being used efficiently. If a firm is making a profit, it suggests that it is producing goods or services that consumers want and are willing to pay for.

4. Consumer and producer surplus: These are measures of economic welfare. Consumer surplus is the difference between what consumers are willing to pay for a good or service and what they actually pay, while producer surplus is the difference between the price a producer receives and the minimum price they would be willing to accept. If these surpluses are high, it suggests that the allocation of resources is desirable.

So, all these tools - the equilibrium price and quantity, incomes of and prices paid by buyers, profits and costs to firms, and consumer and producer surplus - allow economists to determine if the allocation of resources determined by free markets is desirable.