galacticb wrote:
The expense ratios clearly suggest that the TSM fund is the better option for the 401k. However, REIT funds are less tax efficient than TSM funds. I was simply trying to find a way to identify at what point the expense ratio outweighed the tax consequences of holding a less tax-efficient fund in a taxable account.
It was more of a curiosity question than anything. Sorry for all of the confusion.
Yes, you were clear in your original post. I guess my point was that to fully assess the trade-off between tax consequences and expense ratios, it is often necessary to consider the complete life-cycle of the funds. Depending on the specific circumstances, the result may not be linear. I don't believe there is a simple rule of thumb, although in general I believe a reduction in ER can be more beneficial than modest tax-efficiency.
I haven't looked at the scenario you describe above (TSM vs REIT) but I have considered a related situation. Assume that the desired allocation is 100% TSM and there is equal space in the taxable and tax-differed accounts. Also assume that the dividend yield on TSM is 2%, and that the ER is 0.1 in both accounts. The easiest thing to do would be to put TSM in taxable and TSM in tax-differed and be done with it. The 2% dividends in the taxable account will be taxed on an annual basis but these same dividends will be tax-differed in the retirement account.
An alternate approach would be to put TSM Growth (1% dividend yield) in taxable and TSM Value (3% dividend yield) in tax-differed. The combined allocation still would be TSM (Growth + Value = TSM). The reason for doing this would be to take advantage of the fact that Value will be somewhat less tax efficient than Growth and hence will "do better" in a tax-differed account. Using this strategy, one will pay annual taxes on the 1% dividend yield whereas the 3% dividend yield will be tax-differed. If the ER of the Growth and Value funds is the same as TSM (0.1), then this half-and-half approach likely will be better assuming a relatively long investment horizon and similar current and future tax rates. (If applicable, one must also consider the impact of qualified dividends in taxable vs fully taxed dividends in the tax-differed retirement account).
However, ER's on funds that represent the Growth and Value sides of TSM are likely to be higher than a pure TSM fund. The question is, at what point does the higher ER's exceed the tax benefit of this half-and-half investment approach? It turns out that for the scenario of interest to me (my tax rates; 30 year investment period), if the ER's of Growth and Value are only slightly higher (~0.1) than the ER of TSM, then the increased ER's overwhelm the tax efficiency of the half-and-half approach.
In other words, a relatively small change in ER (e.g., 0.1) can easily wipe out the benefits of a tax efficient strategy. Of course, this is only one example where the tax-efficiency of one option isn't that much greater than the other option. It would take a significantly greater ER difference to wipe out the tax-efficiency of having TSM in taxable and REIT in tax-differed (but I haven't quantified this). Still, the conclusion is that seeking low ER's may be more beneficial than trying to use an alternate strategy that is more complex but only moderately more tax efficient.
Sorry for the long explanation. I can be verbose.