However, in the late 20th century—after many decades of relative stability—the labor share began to decline in the United States and many other economically advanced nations, and in the early 21st century it fell to unprecedented lows.
PS: In terms of overall GDP a numbers (edit: not real data) 21% vs 17% may seem more or less stable but that’s a 20% drop or roughly all inflation adjusted per capita GDP growth over the last 20 years.
Sorry, the context was missing. The 21% vs 17% was not meant to be representative of overall numbers. I just recall someone minimizing the impact by referring to some income bracket then comparing it to GDP. My point was simply people overestimate how much per capita GDP is growing, so numbers that look similar can represent large shifts.
However, in the late 20th century—after many decades of relative stability—the labor share began to decline in the United States and many other economically advanced nations, and in the early 21st century it fell to unprecedented lows.
PS: In terms of overall GDP a numbers (edit: not real data) 21% vs 17% may seem more or less stable but that’s a 20% drop or roughly all inflation adjusted per capita GDP growth over the last 20 years.