The concept of tax incidence was initially brought to economists' attention by the French Physiocrats, in particular François Quesnay, who argued that the incidence of all taxation falls ultimately on landowners and is at the expense of land rent. Tax incidence is said to "fall" upon the group that ultimately bears the burden of, or ultimately suffers a loss from, the tax. The key concept of tax incidence (as opposed to the magnitude of the tax) is that the tax incidence or tax burden does not depend on where the revenue is collected, but on the price elasticity of demand and price elasticity of supply.