-
US is about 6o% of global equity markets so a global tracker is pretty US-heavy anyway. I suspect that many people who invest in global trackers may not realise quite how much of it is US vs RoW.
If the US market tanks, a global tracker isn't going to do very well. But then if the US economy tanks, it's going to be a global problem anyway, so even if you don't have direct exposure, you can't easily escape having it indirectly.
It's the individual investor's call if they think the 40% non-US diversification is worth the premium.
is this true even if s&p 500 is cheaper? on InvestEngine -- TER is 0.07 for Vanguard S&P 500 and 0.22 for Vanguard FTSE World ... and lots of overlap (but obvs the former is US heavy, but US tends to be a decent bet?).