In recent days, two very large companies have decided to require that gun buyers be at least 21 years of age [Reuters]. I understand that the government can add age restrictions to sale of certain items. However, can an individual company elect to do so if it is not legally required? Doesn't that amount to age discrimination?
Discrimination is legal, so long as there is not based on a protected category or class(e.g. race, sex, religion).
Age is generally not a protected category. Some states do treat age as a protected category, but:
1) It is generally only in employment, so, for example charging someone differing amounts based on their age is legal (e.g. senior discounts, kids under X are free, etc.).
2) It is generally only protecting higher ages (i.e. discriminating against someone in employment because their age is higher than what you'd like would be illegal, but discriminating against someone because their age is lower than you'd like is not; and in some cases the later is mandatory).
1This would be much more interesting in England and Wales, where age is a protected characteristic in both directions, and the protection applies outside employment. Of course, the particular example that raised the question doesn't apply in England and Wales because supermarkets can't sell guns at all. On the other hand, if Walmart wanted to stop Asda selling alcohol to people aged 18-21, they couldn't. Mar 1, 2018 at 14:18
@MartinBonner: Alcohol may not be the best example, because it's banned by law for anyone under 21 in the US. Knives maybe? But the point remains, it's legal to discriminate, except for discrimination for a reason that is prohibited by law.– sharurMar 1, 2018 at 14:34
6That is why I chose alcohol and the age range I did. Asda is a UK supermarket chain owned by Walmart. Alcohol is legal in the UK for anyone over 18. Discrimination on the base of age is prohibited by law in the UK (for all reasons with specified exceptions). And I agree with your point. Mar 1, 2018 at 14:45