There are four economics concepts that are key to understanding economic decision making: scarcity, supply and demand, incentives, and costs and benefits. Scarcity refers to the fact that valued resources are limited in quantity. Supply and demand, meanwhile, is the relationship between the price of a good or service and the consumer interest in purchasing it, which, for example, can incentivize producers to increase the supply of goods when demand rises and consumers to limit their consumption of certain goods when supplies are scarce. Lastly, cost and benefit is the dynamic between how much a good or service costs to produce/purchase versus the benefit acquired from doing so.