In order to comprehend the ontological construction below, please refer to other my post for all notions in italic.
Perfect price elasticity rules when even very small variation of the price of a commodity leads to indefinite change of its quantity. Any alteration of price for a commodity dramatically shifts the demand or the supply of it. As quantities of the products vary, according to the law of supply and demand, the market price is subject to modification once again, and new adjustment is in order. The price change breaks down the market equilibrium and brings the quantity of the good to zero, because the exchange is no longer possible according to the established market value; subsequently, a recovery to provisional market equilibrium, by the means of a flexible value relationship between commodities, extends the quantity to its maximum.
Historical Backdrop
• LEON WALRAS Elements of Pure Economics: minimum and maximum variations of supply and demand according to the change in price.
• JOAN ROBINSON The Economics of Imperfect Competition: absolute price elasticity.