&gt; how does a spending tax disproportionately affect the poor?<p>Because they need to spend more of their income in order to survive.<p>If you spend all of your income, a 10% sales tax reduces your income by 10%. If you only need to spend half of your income, a 10% sales tax reduces your income by 5% - or less, if the money you don&#x27;t spend earns interest.