The word “luxury” originated from the Latin word luxuria, which means exuberance, excess, or abundance. A luxury good can be identified by comparing the demand for the good at one point in time against the demand for the good at a different point in time, at a different income level. Conversely, when personal income decreases, demand for luxury goods luxury valentines gifts for him even more than income does.

This contrasts with necessity goods, or basic goods, for which demand stays the same or decreases only slightly as income decreases. With increasing accessibility to luxury goods, new product categories have been created within the luxury market, called “accessible luxury” or “mass luxury”. These are meant specifically for the middle class, sometimes called the “aspiring class” in this context. Because luxury has now diffused into the masses, defining the word has become more difficult. Superior goods” is the gradable antonym of “inferior goods”. Some articles in the microeconomics discipline use the term superior-good as an alternative to an inferior good, thus making “superior goods” and “normal goods” synonymous.

Where this is done, a product making up an increasing share of spending under income increases is often called an ultra-superior good. This section does not cite any sources. By this time such lavish bindings were unusual. Though often verging on the meaningless in modern marketing, “luxury” remains a legitimate and current technical term in art history for objects that are especially highly decorated to very high standards and use expensive materials.

Luxury” may be used for other applied arts where both utilitarian and luxury versions of the same types of objects were made. This might cover metalwork, ceramics, glass, arms and armor, and a wide range of objects. The invention of affordable quartz watches caused mechanical watches to become primarily luxury goods. While many handbags are valued on their ability to carry objects, designer handbags are valued based on fashion. Luxury goods have high income elasticity of demand: as people become wealthier, they will buy proportionately more luxury goods.