Now here's a chart looking at service sectors. Average wages for finance, health, and education have risen steadily over the past three decades. Information services took a dip in the 1970s but has risen of late. Meanwhile, average wages in transportation have dropped — particularly after deregulation of the trucking and airline industries in the 1970s:
There's a lot more detail—and many more charts in Mulbrandon's full post, which is worth reading in full. Here's her basic storyline:
Over the last couple of centuries there has been a steady increase in wages for both unskilled workers and production workers. A lot of this growth is a result of the increases in worker productivity due the industrial revolution of the late 1770s and 1800s. However, over the last 40 years, this long-term growth has stopped or slowed down even though the GDP per person continues to grow. At the same time, the growth rate of GDP per worker has slowed compared to the overall growth of the economy.