Workers Should Accept Lower Wages But The Wealthy Won't Work If Taxes Reduce Net Income

Charles Murray's new book reinforces conservative narratives about unemployment. Murray believes that we have unemployment because workers will not accept lower paying jobs. On the other hand, since Ronald Reagan, conservatives have argued that the wealthy will not work as hard if their net wages are reduced by high taxes. If we expect low income workers to accept lower wages and work just as hard, why shouldn't we expect those with high incomes to work harder in order to increase their incomes to replace the income lost to taxes?