Renegade Economist tweets and answers: "Do income tax cuts for the rich make us all richer? See dismal evidence showing this is not true," with a link to this:
and this, showing UK's top 1% through the ages & with projections backward and forward:
and here is the UK's top 1% compared to a few other places:
The author concludes: "The argument that giving the moneyed elite more money will make everyone wealthier manages to ignore the roaring evidence of the past."