Bonds are typically less tax efficient than stocks, leading to a common recommendation to hold bonds in retirement accounts and stocks in taxable accounts. This article challenges this advice for certain investors.
This article applies if you follow a plan devised by Quality Asset Management, or:
- You optimize your use of bonds: Income during stock declines and no other use.
- Your stock investments are highly diversified globally, with no market timing and no individual stock selection.
- Your stock investments have high average returns and a low turnover (i.e. limited annual sales of stocks; e.g. index mutual funds).
Bonds are less tax efficient than stocks
The notion that bonds are less tax efficient than stocks is the basis for the idea that bonds are a better investment to shelter from taxes, by putting them into retirement accounts. This notion is correct as seen in the table below:
| Bonds (mainly interest) | Stocks (mainly capital gains) | |
| Taxation frequency | Done every year | Mainly deferred to sale. Index funds hold each stock for a number of years on average. |
| Tax rate | Ordinary income tax rate | Mainly long-term capital gains |
A deeper analysis can challenge the conclusion above.
Considering investment horizon
Given that you use your bonds whenever there are stock declines (assumption #1 at the top), as soon as you experience a stock decline, you would withdraw the money, and would not be able to put it back in. This would result in losing the retirement account tax benefit forever, due to a single stock decline.
There is a sophistication that can help you get around this limitation, but is not very practical due to its complexity and excessive trading.1
Comparing tax amount instead of tax rate
While the tax-rate of bond investments is higher than stocks investments, there is an offsetting factor. The average growth rate of stocks is much higher than bonds, magnifying the total tax amount , and offsetting the benefit of the low tax rate . A full analysis may become complex, given the combination of long-term gains and short-term gains, dividends and capital gains distributions. Instead, I will provide a simplified example to demonstrate the point:
- The tax on a bond fund with 5% interest at about 40% tax rate (federal 35% & state 10% minus a deduction of state taxes from federal taxes) is 2%.
- The tax on a stock fund with 15% growth taxed at 10% tax rate (federal 15% & state 10% minus 15% for the fact that taxation is mostly deferred) is 1.5%.
The faster growth of the stock investment keeps raising the tax amount. If we start with a $10,000 investment, here is the tax amount over a few years (under the assumptions above):
| Tax on $10,000 investment in bonds vs. stocks | Difference | ||||
| Year | Bonds (5% growth 2% tax) | Stocks (15% growth 1.5% tax) | |||
| Principal | Tax | Principal | Tax | ||
| 1 | $10,000 | $200 | $10,000 | $150 | -$50 |
| 2 | $10,300 | $206 | $11,350 | $170 | -$36 |
| 3 | $10,609 | $212 | $12,882 | $193 | -$19 |
| 4 | $10,927 | $219 | $14,621 | $219 | $0 |
| 5 | $11,255 | $225 | $16,595 | $249 | $24 |
| 6 | $11,592 | $232 | $18,835 | $283 | $51 |
The faster growth of the stock investment resulted in a higher tax amount within 5 years, despite the lower tax rate.
While this example ignores some variables, and has simplified assumptions, it demonstrates the point that higher growth can result in higher taxes, even when the tax rate is lower and most of the taxation is deferred.
Summary
The rule of thumb: “hold bonds in retirement accounts, due to their worse tax treatment”, does not hold for investors that optimize their bond and stock investments, for two main reasons: (1) when withdrawing bonds from the retirement account during stock declines you lose the tax benefit forever; (2) the higher growth of stocks results in higher tax amounts over time.
1 Say you need $10k from bonds during a stock decline. You can do the following:
Taxable account: sell $10k stocks
Retirement account: sell $10k bonds, buy $10k stocks
Once your stock portfolio recovers, you can move the stocks in the retirement account back to bonds (sell $10k stocks, buy $10k bonds).
Disclosures Including Backtested Performance Data