Hard to say, the earnings yield I assume is the inverse to the PE ratio. 2009 Yields shot up as share prices crashed, interest rates were forced down to stop a depression.
Not that I think anyone can predict the future. From the chart there has been an inverse correlation since 2009. I guess in the eighties high interest rates affected company profitability. The nineties there was a balance between lending money and dividend yields.In the early 2000sthe mining and property booms pushed up profits and interest rates. I conclude this chart gives me no idea what will happen next. But at a guess if you are taking more risk owning companies than fixed interest the earnings yield should stay above the 90 day rate but reading the likes of Marc Faber, Jim Rogers and a few others holding $us or US govt bonds could be one of the riskiest things you could do. Aussie and NZ I don't think are as bad as our govts are trying to get their budgets balanced and they don't have central banks pumping up the money supply to the same degree as the rest of the world.
I should be like most posters on this website, looking at individual companies and finding opportunities. Instead I am procrastinating waiting for a deflationary crash before buying undervalued blue chip companies. When in fact we could quite easily end up with rampant inflation and me missing the boat even more.