National income can be likened to a pie. If between one year and the next the pie gets bigger, everyone can have a bigger slice. But if, instead, the size of the pie stays the same, a bigger slice for some can only mean a smaller slice for others.
This helps us understand the present dismal state of the U.S. economy and the impetus behind Bernie Sanders’s electoral campaign, which is aimed at the needs of workers and working families. For decades, U.S. economic growth has stagnated, with each succeeding decade experiencing a lower rate of growth. Under these circumstances, the rapidly increasing income of those at the top — or what Sanders likes to call the “billionaire class” — is at the expense of the income shares (slices of the pie) of those at the bottom.