The post-WW2 period was an economic anomaly in which the U.S. was able to dominate almost every industry in the world because we were the only industrial giant that had emerged from the war with our industrial capacity unscathed. That transition period pretty much ended by the late 1960s, if Japan's emergence as a manufacturing power is any indication. It's no coincidence that the late 1960s also marked the start of the economic malaise in this country that lasted until the early 1980s.
This is where your analysis is only partially correct, and the part that is incorrect actually reinforces my point. The United States did not have the highest standard of living in the world throughout the 1970s -- as indicated by the two fuel crises, spiraling inflation, and stagnant economic growth that afflicted us for almost the entire decade.
While I can accept the possibility that "standard of living" is a fluid concept, I can NOT accept this statement at face value.
Please provide a source, or stats.