Two new age-based investment strategies can improve the return on investment for 529 college savings plans without significantly increasing the investment risk. In some cases the investment strategy may even reduce investment risk. 

Investment risk is largely unavoidable, if one has long enough of an investment horizon. For example, the stock market will drop by at least 10% at least three times during any 17-year period from birth to college enrollment. At least one of those stock market “corrections” will involve a drop of 20% or more, known as a bear market. 

Age-based asset allocation 

College savings plans offer age-based asset allocations as a way of managing this risk. When the child is young, an age-based asset allocation starts with an aggressive mix of investments, which offers a greater return on investment, but also a greater risk of loss. Less money is invested, so potential losses are limited, and there is also more time available to recover from losses. As the investment grows and more money is at risk, an age-based asset allocation gradually shifts to a more conservative mix of investments. As the child approaches college age, most of the portfolio is invested in asset classes with a low risk of loss. 

A typical age-based asset allocation starts off with 80% of the portfolio invested in stocks, periodically reducing this percentage until only 20% of the portfolio is invested in stocks. 

But, traditional age-based asset allocation strategies for college savings shift to a conservative mix of investments too quickly. A better approach involves sustaining an aggressive mix of investments for several years before transitioning to an age-based asset allocation. The age-based asset allocation is compressed to fit the remaining investment horizon. Since the portfolio is maintained in a higher risk profile only during the first few years of the investment glide path, the increase in overall risk is minimal and may be offset by the higher return on investment. 

Delaying the onset of age-based investment

Delaying the onset of an age-based asset allocation by up to 10 years can increase the annual return on investment by as much as one percentage point, without significantly increasing the investment risk. Each year of delayed onset increases the annualized return on investment by about 0.1 percentage points (10 basis points). These investment strategies were evaluated using all 204-month (17-year) periods from 1950 to 2017. Although past performance is not necessarily predictive of future results, this analysis can provide insights into the typical range of investment performance. 

Delaying the onset of an age-based asset allocation by up to 10 years improves overall investment returns without significantly increasing the investment risk. The investment risk grows significantly if the onset of the age-based asset allocation is delayed by 11 or more years. 

The improvement in performance is the equivalent of as much as a percentage point increase in the annualize return on investment. This could yield as much as an 8% increase in total college savings over a 17-year investment horizon.


Increasing investment risk during the early years

Increasing the initial percentage of the portfolio that is invested in high-risk investments from 75% or 80% to 100% can also improve investment returns without much of an impact on risk. Again, this is because the more aggressive mix of investments is maintained only during the first few years of the investment glide path, when less money is at risk of loss. 

These charts show a linear glide path that shifts from 80% stocks to 20% in increments of 3.75% percentage points and a linear glide path that shifts from 100% stocks to 20% in increments of 5.0% percentage points. 

Linear Glide Path, 80% to 20%

Age-based asset allocation

Linear Glide Path, 100% to 20%

Age-based asset allocation

The next two charts show the linear glide path that shifts from 80% to 20%, but with a five-year and 10-year delayed onset. The compressed age-based asset allocations use increments of 5.0% and 8.6% percentage points, respectively. 

Linear Glide Path, 80% to 20%, 5 year delayed onset

Age-based asset allocation

Linear Glide Path, 80% to 20%, 10 year delayed onset

age-based asset allocation

Impact on investment earnings

These investment glide paths were evaluated using a total of 600 investment glide paths instantiated with historical stock market data from 1950 to 2017. 

This table shows that the Linear 100% to 20% investment glide path demonstrates superior investment performance as compared with the Linear 80% to 20% investment glide path. The average earnings were $3,153 higher, assuming monthly contributions of $250. 

Asset allocationMinMaxAverageStandard
deviation
Annualized
ROI
Average
earnings
Linear 80% to 20%11.1%44.3%26.5%9.6%3.4%$19,642
Linear 100% to 20%11.3%48.5%29.1%11.0%3.8%$22,795

The investment risk was also lower. None of the 600 test scenarios involved an investment loss. The minimum return on investment was higher (11.3% vs. 11.1%) and the maximum return on investment was higher (48.5% vs. 44.3%). The percentage of the test scenarios that involved less than a quarter of the total savings coming from earnings was also lower (41.6% vs. 48.1%). 

This table compares the impact of a delayed onset on the investment performance. The average return on investment increases with a greater delayed onset. A five-year delayed onset corresponds to half a percentage point increase in the annualized return on investment and a 10-year delayed onset corresponds to a full percentage point increase. The latter is the equivalent of about an 8% increase in total college savings over a 17-year investment horizon. The average earnings for a five-year and 10-year delayed onset were $3,660 and $8,796 higher, respectively. 

Asset allocationDelayed onsetMinMaxAverage
Standard 
deviation
Annualized
 ROI
Average 
earnings
Linear 80% to 20%None11.1%44.3%26.5%9.6%3.4%$19,642
Linear 80% to 20%5 years10.9%49.0%29.5%11.4%3.9%$23,302
Linear 80% to 20%10 years8.9%55.9%32.8%14.0%4.4%$28,438

Although the minimum return on investment was lower, none of the scenarios involved investment losses. The percentage of age-based investment scenarios with less than a quarter of total savings coming from earnings was also lower (48.1% vs. 41.8% vs. 37.3%). 

This chart shows the distribution of the performance of the 600 test scenarios for 0, five and 10 years of delayed onset. Increasing the number of years of delayed onset causes a flattening out of the middle of the distribution, shifting the scenarios toward a higher percentage of total savings coming from earnings. 

Histogram of earnings as a percentage of total savings for delayed onset of age-based asset allocation, 1950 to 2017

Age-based asset allocation
 

This approach demonstrates several new insights that can be applied to saving for college, retirement and other life-cycle events.

  • The return on investment for an age-based asset allocation investment glide path can be improved without significantly increasing the investment risk by transforming the investment glide path.
  • One approach transforms an age-based asset allocation by delaying the onset of the shift to a less aggressive mix of investments by a number of years and compressing the original glide path to fit into the remaining available investment horizon.
    • A delayed onset of five years yields the equivalent of a 0.5% percentage point increase in the average return on investment.
    • A delayed onset of 10 years yields the equivalent of a 1.0% percentage point increase in the average return on investment.
    • Investment performance for a 17-year age-based asset allocation improves incrementally for each additional year of delayed onset up to 10. (The investment risk starts to increase significantly with 11 or more years of delayed onset.)
  • Another approach starts the age-based asset allocation at 100% stocks when the child is young instead of a smaller percentage (e.g., 80%), yielding superior investment returns without significantly affecting investment risk. That’s the equivalent of a 40 basis point improvement in the annualized return on investment. 

Additional details can be found in a paper that is available at www.studentaidpolicy.com/asset-allocation/.