Eureka, I've found my own personal investment performance benchmark!

Tonight, I was reading one of my favorite authors on Seeking Alpha commenting on another author's article about the relative contribution of dividends to investment performance over time. He made the point that if you reinvest dividends, over time an increasing amount of total return is attributed to the dividend-derived portion of your position.  That assumes, of course, that you purchase an original position and then tabulate the portion of your total return that comes purely from the capital gains attached to your original purchase, and attribute all additional returns (capital gains and dividends) from stocks purchased with dividends to the dividend-derived return.

Interestingly, since the goal of the dividend-growth investor is a rising stream of dividends, an interesting benchmark is the dividend-doubling time, or DDT as I have named it. After all, if one wants to live on dividends and distributions alone in retirement, the faster one gets to replacing one's earned wages with dividends and distributions, the sooner one can ditch one's work clothes for a bathrobe early every morning.

The rule of 72 defines how quickly a pot of money doubles if it earns compounded interest.
7% per year takes 10 years to double. 10% per year takes 7 years to double.

What rule describes the doubling time of dividends?  First, one has to set out some requirements for the rule. One rule applies if one takes the dividends as cash. Another rule applies of one is reinvesting the dividends. Applied to a single stock, one must use a DRIP to determine the DDT for that stock.
Within a portfolio, the DDT could be achieved DRIPing every stock, or collecting dividends and reinvesting selectively. 

For the sake of simplicity, I will assume the rule applies to a single stock in a DRIP program.
Simply stated, whatever the cash yield of a holding at the time you establish your position, the point at which you are collecting 2x that amount of cash, you have your Dividend doubling time. That time is closely related to a concept called yield-on-cost.  If your starting yield is 3% and your yield on cost is 6%, then your dividend stream should have exactly doubled in that interval.

We all know that yields don't double as a company adjusts it's dividends over time. When earnings rise, stock price generally rises as well. When a discrete dividend increase occurs, it has an effect on stock price as well. Since using a DRIP requires that you purchase incremental shares at whatever price prevails at the time the dividend is paid, the incremental purchases have differing claims on future earnings and dividends. If one presumes a constant yield, i.e. the company raises dividends exactly in proportion to rising earnings, and the market re-prices the stock precisely in proportion to rising earnings, then one can relatively easily calculate the point at which the actual cash dividend payment doubles. However, we have this phenomenon of margin expansion and contraction that undulates somewhat unpredictably over time, so a formula will only approximate the real-life DDT of a given stock at any time in history.
Still; the concept is important because real money is what we use to pay our bills;  Currently, the cash  yield of all my stock holdings is roughly enough to pay the mortgage on my home. If I want to retire on dividends and distributions alone, I need to reach a point where those dividends cover all my expenses, after taxes. I'll need about 4-fold more dividends, or two doubling times. How long will that be?  The simplistic view is to assume that my current yield will stay about the same, so I'll need to quadruple the value of my portfolio in order to retire. I think that won't actually be the case. I think that the combination of dividend growth, as well as the compounding effect of dividend re-investment will get me there faster than a simple compounding calculator would predict. However, since rising stock price will dampen the effect of the DRIP in regards to the rate of increase in share count one might expect from the DRIP, the calculation must take that into account.  That means that things like share-repurchases, which drive earnings per share and share price may also have to be considered in the equation. Rising earnings per share drives rising dividends per share, as long as the payout ratio remains constant. It may not be constant, however. That is a decision made in the board room, not by some formula.  Formulas will never do more than approximate reality, so watching the actual cash numbers makes more practical sense than relying on formulas.

Now I'm off to figure out the dividend doubling time of a few of my holdings! I'll be reporting back soon....