Yes, you lose money (or more precisely you lose opportunity) but you gain certainty. Which is what you want for retirement
That’s pretty much the definition of risk premium.
If you have more than enough saved to meet your basic needs, it does (IMO) make sense to give up some total income for lower variance.
Stocks generally rise with inflation, whereas bonds continue paying out the same nominal amount, which buys you less over time.
As a retiree I'm 50/45/5 in stocks/bonds/cash, having opted for a conservative portfolio. The stocks are the only reason I haven't lost buying power. But the bonds have performed so poorly that I've barely kept up with inflation despite the amazing bull run in stocks.
Currently you get 2.75% yield in real terms for the 30 year maturity: https://www.cnbc.com/quotes/US30YTIP
Are you referring to Anarkulova et al? Might be worth mentioning that the fixed income part is replaced with international equity, not more domestic equity.
Another good option for something that can give good current income is REIT stocks. The management fees on the funds that specialize in these tend to be high for my tastes (I like passively managed funds with management fees that could be rounding errors) so when I’ve had money in REITs, I’ve typically looked at the top stocks in the REIT funds and just bought those directly with dividend reinvestment. Note that because of the nature of REIT dividends and taxes, it’s better to use tax-advantaged accounts to buy these than to put money in a regular retail account towards them.²
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1. Back during the first dotcom goldrush when tech stocks were especially volatile (1999–2001 in particular), people who bought dotcom mutual funds in taxable accounts often ended up with a big distribution from the fund and a drop in share price greater than that distribution so that they would end up not only losing money on their investment but they also had a tax bill for their troubles since distributions will count as realized capital gains.
2. Important to note that I’m not a financial advisor and my advice is probably garbage.
Also, it should be noted, just because it's the optimal to have the most $'s that shouldn't be the goal. The goal should be to survive your retirement with "enough".
And it should also be mentioned, most people can't stomach holding 100% equities, for a very good reason. When the 40-60% market crash happens, people get emotional and make emotional decisions. Sure there are the lucky few that can hold out, but most can't. Are you going to be one of the few lucky ones? If you haven't yet been through it once(last one in the USA was 2008/9), how do you know for sure?
People have forgotten this but equities are an infinite duration asset that are prone to periodic, significant, often violent crashes.
(Edit: often at a time when everyone is absolutely convinced they're the best asset class...)
You can keep some equity exposure but you don't want 1929 or 2008 to happen the day after you retire when you might live for another 30 years
That's assuming you sell the bonds before their end.
Bounds are not as volatile, so even if you lose some money from inflation, you are less likely to lose a lot of money, money you need to live, from the whims of the market. You want to protect your capital, yields don't matter as much if you near the end of your life.
If you are younger, and you make reasonable investments and not gambles, you can expect that your value will go up (more so than with bounds) within a decade or two, and because you have income, you don't need that money and you can wait for the market to recover before selling.
To point, the economic uncertainties around geopolitics, AI, and war, plus irresponsible debt spending by governments and the prospect of QE (and higher inflation), is pushing long term rates steadily higher. There’s a reasonable chance that 30y treasuries are nearing 6% by the end of next year. Remember that rates and bond prices are inversely related. Anyone who holds bonds in this market will likely lose money. Holding to maturity won’t help much either because if inflation continues to rise, as is a major concern, most or all of that 5% yield gets eaten.