My understanding (and I'm no economist) is that (a) some of the productivity metrics are weird, because they compare with the US which counts their idiotic for-profit healthcare sector in productivity, (b) part of the low investment is caused exactly because our capital is tied in real estate, and (c ) low investment is also a result of our god-damned oligopolies in so many key sectors of the economy. High taxes is not the only tool of course. What we need is a very aggressive policy against the wealthy. That can take the form of taxes, of improving social mobility via the welfare state, and of breaking up their cartels, i.e., their stranglehold on the economy.