Correlation != Causation. There are many reasons for this that have very little to do with the Gold Standard. I would suggest that technology itself has caused much if not most of this, as has the destruction of Unions, deregulation, and yes government corruption. But I've yet to hear a plausible explanation for how the Gold Standard somehow maintained wages in line with GDP. The only somewhat plausible reason I see here is that a free currency encouraged a move to assets, which protected the rich against inflation somewhat better than the rest.