when are two goods said to be substitutes of each other
Substitute good A substitute goods is one goods that can be used instead of another. In consumer theory, substitute goods or substitutes are products that a consumer perceives as similar or comparable, so that having more of one product makes them desire less of the other product. Formally, X and Y are substitutes if, when the price of X rises, the demand for Y rises.
Sale of Goods Act 1979 The Sale of Goods Act 1979 (c 54) is an Act of the Parliament of the United Kingdom which regulated English contract law and UK commercial law in respect of goods that are sold and bought. The Act consolidated the original Sale of Goods Act 1893 and subsequent legislation, which in turn had codified and consolidated the law. Since 1979, there have been numerous minor statutory amendments and additions to the 1979 Act. It was replaced for consumer contracts from 1 October 2015 by the Consumer Rights Act 2015(c 15) but remains the primary legislation underpinning B2B transactions for selling / buying goods[citation needed].