Will Trice -
If my numbers are correct THIS time, you caught me being sloppy and posting something mathematically incorrect - significantly incorrect - I tried a shortcut that didn't work. I still find it hard to believe that selling at 15% gives a significant advantage if tax rates subsequently increase. But I have the equations below so anyone can check them.
Two guys, Abe and Bill hold an indentical investment position with
100k long term capital gain. Abe sells in 2008 to pay a 15% tax rate and immediately reinvests the remaining 85k. Bill simply holds onto his existing position. The problem is to determine who ends up with more cash in his pocket at some future date when they both sell. The variables are the rate of return, the future tax rate, and the number of years. Rich Carreiro specified "substantial" gains so I think it's not unreasonable to assume a full 15% and full 28% effective tax rate. I also think an 8% rate of return is reasonable.
Y = number of years Ry = rate of return compounded over Y number of years (it should be a superscript, representing the rate of return to the power of Y) T = future tax rate P = present tax rate
Bill = 100,000 x Ry x (1-T) Abe = (100,000 x (1 - P) x Ry - 100,000 x (1 - P)) x (1 - T) + 85,000
In our example, P = 15%, T = 28%, R = 8%.
Y = 1 years (2009)
Bill = 100k x 1.08 x 72% = 77,760 Abe = (100,000 x 0.85 x 1.08 - 100,000 x 0.85) x 72% + 85,000 (91,800 - 85,000) x 72% + 85,000 = 89,896
In English, for Abe, first we reduce the capital invested by 15% tax paid, then apply the rate of return. To determine the taxable portion of that return, we subtract the established cost basis of 85k, then take out the 28% tax leaving 72% of the new capital gain. Then we add back the 85k cost basis to get final or total realized profit, so that we can compare that total to Bill.. Abe = (85k x Ry - 85k) x 72% +
85k.
Y = 11 years (2019)
Bill = 100,000 x 2.331639 x 72% = 167,878 Abe = (100,000 x 0.85 x 2.331639 - 100,000 x 0.85) x 72% + 85,000 (198,189 - 85,000) x 72% + 85,000 = 166,496
There must be a more elegant formula for this, but I haven't found it yet. I think the above works.
The higher the rate of return, the less time it takes to make up the presumed tax increase, and conversely, the higher the increase in the tax rate, the longer it takes. In the real world, even considering all the variables and assumptions (the tax rate might be decreased, or remain the same, for example), it does appear to make sense to at least consider taking profits at the 15% rate. Clearly if one thinks the market might drop, then realizing gains to establish a higher cost basis would result in a capital loss that could be used to offset other gains, and not simply a reduction of gains if the cost basis remains untouched.