An ersatz good is a substitute good, especially one that is considered inferior to the good it replaces. It has particular connotations of wartime usage.
Advertisement for ersatz coffee (containing some coffee beans) in 1926
Ersatz bread from World War I on display at the Imperial War Museum in London
Ersatz food from the siege of Leningrad, made from goose-foot seed and bran, and fried in mineral oil
In economics, an inferior good is a good whose demand decreases when consumer income rises, unlike normal goods, for which the opposite is observed. Inferiority, in this sense, is an observable fact relating to affordability rather than a statement about the quality of the good. There are many examples of inferior goods, including cheap cars, public transit options, payday lending, and inexpensive food. The shift in consumer demand for an inferior good can be explained by two natural economic phenomena: the substitution effect and the income effect.
An item such as non-branded grocery products are common inferior goods. There is no set criteria of what constitutes an inferior good, but economists refer to an inferior good as any item preferred less when disposable consumer income increases.
