When people buy less of a certain good as their income increases, this good is considered

An inferior good

Explanation:

When a good has a more expensive substitute (either because it is of better quality or gives you more status) and it's demand increases when the income improves we can figure out which the inferior goods are. The inferior goods are the ones that are replaced when this occur. So the demand drops when the income improves.  

answer; nonpartisan election;

answer; being clearly political;