Investing. The impact of low interest rates

How might low real rates boost the equity market? There are two theoretical explanations. The first relates to the fact that equities should be priced as the value of future cashflows, discounted to the current day by an interest rate.* Lower that discount rate and you raise the present value of shares. I have argued that this rationale is flawed; if rates are now because economic growth is slow (and it has been), then one needs to lower the estimate of future cashflows. The effects cancel each other out. The second reason is simple asset switching; low rates on bonds and cash make investors seek out the greater attractions of equities; this may well be the driving force behind 2013's equity rally.