The role of economic growth in advanced democracies is not mainly the accumulation of more material goods. By any historical norm, even today's poor are staggeringly wealthy.

XEconomic growth plays a more subtle role. It gives people a sense that they are getting ahead and are in control of their lives. It serves as the social glue that holds us together and counteracts -- to some extent -- the influences of race, class, religion, ethnicity and geography, which drive us apart.

But what if economic growth can no longer perform this vital function? What if the economy has entered a prolonged period of slow growth that frustrates millions of Americans? What if the glue no longer holds? These questions are already posed by rising economic inequality. Now the debate enters a new phase with the release of President Trump's first annual economic report and the more scholarly Report of the Council of Economic Advisers (CEA).

These documents frame the economic debate between Trump and his detractors. "The (Trump) economic forecast ... is the most absurd I've ever seen," Harvard economist Jason Furman, chairman of President Obama's CEA, told Vox's Dylan Matthews. Trump's economists estimate the economy will grow 3% annually for the next decade; Furman and others say about 2%t. The difference is huge.

To understand the debate, look at the table below. As it shows, economic growth can be separated into two factors: labor force growth -- the number of workers; and workers' productivity (efficiency) -- what they produce. Add these factors together, and you get the economy's overall growth rate.

The figures portray history. In the first decades after World War II (1950-1973), both the labor force and productivity grew rapidly. Women were beginning to take paid jobs in large numbers.