The paper quoted (and my own philosophical bias against too much cash) have half-convinced me to do what I've been slowly attempting to do: decrease the portfolio cash built up since 2010. (I built up cash before the 2008 crash, put some to work during that crash, didn't reinvest some dividends/LT/STgains, and sold some in 2010-early 2012 on the way up, so I'm currently up to 22% cash if you don't count the taxable savings, which would bring it up to about 30%.
I would keep a year of cash, just for the peace of mind and probably replenish when the portfolio gains are particularly strong (last March or April for instance).
One could use the short-term bond to replenish in a bear market plus I plan on sweeping dividends and some LT/ST gains to fund expenses. I can also see building up cash in anticipation of a market drop; I've been there for more than two months, but now I'll just put cash to work where I think the values are particularly attractive, while waiting for a drop elsewhere.
Other than regular rebalancing, what cash replenishment strategies are out there? Maybe this should be a new thread.