In direct inflation terms the minimum wage was ~10.50 / hour in 1968 or around the current minimum wage in France. Though as a percentage of the economy it was more than 20$/hour. Thus, it's not quite as clear cut as you are suggesting.
PS: Inflation is not really a single number as some but not all things end up costing less to produce over time. In other words, A may get more expensive while B becomes less expensive. Which makes long term inflation calculations more complicated.
Despite the fact that political language in the United States confuses this, 'Western Liberalism' is not the same thing as 'Progressivism'. Western Liberalism is about liberal democracy combined with free-ish markets. This can come with a minimum wage, or it might not. It encompasses the vast majority of the political landscape in most Western countries and everyone from American conservatives and to British labour fall under its domain.
Re:The deep roots of modern resentment
by crdoconnor on Wednesday February 01, 2017 @08:48AM
(#13540637)
I don't quite believe I'm hearing somebody say "aside from one of the 3 Presidential candidates who were all in the news constantly, nobody said this so nobody has EVER advocated for it".
The fact that the corporatist extremists ("moderates" like Obama and Clinton) squeeze this kind of idea from the public discourse is exactly what led to declining incomes which in turn is what made people furious enough to vote for Trump.
I don't know how you came to the conclusion of western liberalism being against raising the minimum wage when it's been a core tenet of their platforms for over a decade now.
But to $20 an hour is something neither liberal nor conservative has EVER advocated for as until there is a public uproar for it, both will always side with corporate interests.
That said, your proposition is an alternative solution that I have never heard anyone of actual influence from either side of the political spectrum (outside of Sanders) ever bring up.