The reason the wealthy spend less of their income is they have more than they need, and they put the rest into investment, which increases their own wealth. In

The reason the wealthy spend less of their income is they have more than they need, and they put the rest into investment, which increases their own wealth. In fact, that is the basic conservative argument as to why the government should let the rich keep their income. The idea is that investment by the wealthy increases total size of the national economy, which in turn leads to everyone's income going up. The problem is that this process hasn't been working for about three or four decades. The rich keep investing their money and getting richer, but income for most other people is stagnant or going down.