Individual retirement account allocations tend to vary by age and account balance, but not much by gender, according to a new study.

The report, by the Employee Benefit Research Institute, found that those IRA owners who are older, have higher account balances, or own a traditional IRA that originated as a rollover had, on average, lower allocations to equities. As account balances increased, the percentages of assets in equities such as direct ownership and mutual funds, and balanced funds including target-date funds, combined decreased, while bond (i.e., direct ownership, mutual funds, etc.) and “other” (i.e., real estate, annuities, etc.) assets’ shares increased.

Equity allocations for the youngest IRA owners (under age 35) with small account balances were the lowest across the age groups. However, when balances reached $10,000 or more, younger IRA owners had significant increases in equity allocations, such that those ages 25−34 with the largest account balances had the largest equity allocation.

“Those under age 45 were much more likely to use balanced funds than were older IRA owners, and those under age 35 with balances less than $25,000 had particularly higher allocations to balanced funds,” said EBRI senior research associate Craig Copeland, who wrote the report. “This shift follows the standard investing ‘rule of thumb’ that individuals should reduce their allocation to assets with high variability in returns (equities) as they age.”

Roth IRAs had the highest share of assets in equities (59.1 percent) and balanced funds (15.5 percent). Traditional-originating from rollovers IRAs had the lowest percentage in equities (at 41.3 percent), but also had the highest percentage of assets in money (12.8 percent) and the highest percentage in bonds. Roth IRA owners were also much more likely to have 90 percent or more of their account invested in equities than owners of the other IRA types.  IRA owners who also were ages 35‒44 or had account balances of less than $10,000 were more likely to have extreme allocations (more than 90 percent) to equities.

Overall, as of year-end 2010, approximately 46 percent of total IRA assets were in equities, 20 percent in bonds, 11 percent in balanced funds, 9 percent in money, and 15 percent in “other” investments.

The full report is available in the October 2012 edition of EBRI Notes, available at www.ebri.org.