I've also used that link in the past, but in digging more into the data I think there may be some problems with those data - perhaps that they only consider hourly wages, and not compensation. These [1] data from the Federal Reserve Bank of St. Louis, and are just a cleaner representation of direct Bureau of Labor Statistics data. That is Nonfarm Business Sector: Real Compensation Per Hour. And you can see it has been consistently increasing - up about 50% since 1970.
Nonfarm business sector is defined as: The nonfarm business sector is a subset of the domestic economy and excludes the economic activities of the following: general government, private households, nonprofit organizations serving individuals, and farms. The nonfarm business sector accounted for about 77 percent of the value of gross domestic product (GDP) in 2000.
---
Another important metric is that in the US there has been a sharp upward trend in wealth of society. I ran into this [2] when actually searching information on the chiseling out of the middle class. And that paper does describe that chiseling of the middle class. In 1979 the middle class controlled 46% of all income, and the upper/rich classes controlled 30%. Today (well at least today as of 2014) the rich and upper class control 63% with the middle class left with 26%. There's even been a chiseling out of the middle class as a whole declining from 38.8% of society to 32% of society.
But the eye opener is this. This is the change in the size of each economic group between 1979 and 2014 as a percent of the total population:
- Rich: 0.1% -> 1.8%
- Upper Middle Class: 12.9% -> 29.4%
- Middle Class: 38.8% -> 32%
- Lower Middle Class: 23.9% -> 17.1%
- Poor or Near-Poor: 24.3% -> 19.8%
These data are certainly not indicative of flat lining of real earnings. Statistics like this are certainly subject to biased interpretation and 'massaging'. If one is curious about the source, wiki has a section on the political stance of the Urban Institute [3]. Though the paper itself is very transparent in their methodology and extremely readable. I found it all eye opening to the point that it actually changed my worldview.
---
I'm unsure what exactly what causes the biggest skewing of Pew's numbers. It could be that perhaps we have a greater relative ratio of workers that are excluded from their numbers (for e.g. occupying 'supervisory' roles), or it could be that compensation beyond wages itself has just become much more valuable. It's also possible that their numbers are reasonable but the labor force dynamics make them misleading. For instance imagine if a smaller chunk of society counts as part of the labor force or that the labor force participation rate declines. Still considering wages just within this segment of society would not really indicate the changes for society at large. In any case, and for whatever the reason, those those data are not really indicative of the economic direction of the nation.
[1] - https://fred.stlouisfed.org/series/COMPRNFB
[2] - https://www.urban.org/research/publication/growing-size-and-...
[3] - https://en.wikipedia.org/wiki/Urban_Institute#Political_stan...