regressive
adjective formal uk/rɪˈɡres.ɪv/ us/rɪˈɡres.ɪv/
(TAX)
finance & economics specialized（税收）递减的（对富人的影响比对穷人的小）
(of tax) lower on large amounts of money, so that the rich are less affected
Regressive taxation means that poor people wind up paying a larger percentage of their income in tax than rich people do.
The single most regressive tax is the tax on food because everyone has to eat.