Fair valuation of US stocks?

[markrmau]

US stocks typically trade at higher PE and lower yield than AUS stocks.

I understand that this is because tax laws in US strongly favour capital gain over dividend payments. (is this correct?)

So what would an equivalent ratio be? ie Aus P/E 15, Yield 3% == US P/E 20?

Given the recent profit upgrades, is S&P500 undervalued?

[salz]

ABN Amro looks attractive to me.

[Smurf1976]

It is my understanding, from reading the comments of various analysts and others over the years, that the long term average P/E for US stocks is 14. Aound 7 at the bottom of a bear market, 28 and above being offical bubble territory.