This pattern is quite different from that in most countries, where the young borrow against future income and the elderly run down the savings they accumulated in their high-earning middle years.
The two concepts are different: income is the flow of money a nation or household receives in a year; wealth is the stock of assets it has accumulated over its life so far, minus its debts.
The U. S. tax system discourages saving in many ways, such as by heavily taxing the income from capital and by reducing benefits for those who have accumulated wealth.