Just how well have 401(k) investors fared over the recentyears?

Updated research from the non-profit Employee Benefits Research Institute,a leading analyst of the defined contribution market, shows thatsavers who have been in the same plan since 2007 are making outquite well.

The new data differentiates participants in the EBRI databasethat have consistently stayed invested in one 401(k) plan since at least 2007.

That database, which was designed in conjunction with theInvestment Company Institute, tracks about 26.4 millionparticipants.

About 19 percent, or 4.2 million of those participants held thesame 401(k) account between the end of 2007 and the end of 2013.The EBRI/ICI analysts call them “consistent” participants.

The new report shows that consistency is clearly payingdividends.

By the end of 2013, the consistent cohort had accrued largeraccount balances when compared to the overall cross-section ofparticipants in the database.

Nearly a quarter, or 23.5 percent of consistent participants hadmore than $200,000 in their 401(k) accounts at the end of thesix-year period tracked, while only 10 percent in the overalldatabase had as much.

Another 18.8 percent of consistent participants had amassedbetween $100,000 and $200,000, compared to the 9.6 percent in theoverall database.

After six years of consistent participation, the average accountbalance was $148,399, more than twice the average balance of$72,383 in the entire database.

The median balance was $75,359 with consistent participants,more than four times the median balance of the entire accountstracked, which was $18,433.

Overall, average balances of consistent savers experienced a10.9 percent rate of annual compound growth between 2007 and 2013,in spite of the massive losses in 2008, when the average 401(k)balance fell more than 25 percent.

Those increases blow away the annual gains experienced by therest of the database. For all participants, the average balance wasabout $64,000 in 2007. By 2013, that average had only grown about$7,000, to an average of $72,383.

How is the group of consistent participants demographicallydistinct?

For one, they are older. By the end of 2013, only 2 percent werein their 20s and only 18 percent were in their 30s.

And 36 percent of the consistent group was in its 50s, while 14percent were in their 60s.

Far more younger participants are represented in the entiredatabase, as 13 percent of all participants are in their 20s, and23 percent are in their 30s.

Clearly, age benefits the account values of older participants.So does staying with the same employer.

In the consistent group, 42 percent of participants had 10 to 20years of tenure with their existing employer, and 29 percent hadmore than 20 years.

In the overall database, 37 percent had five or fewer years oftenure.

The new study complements the EBRI/ICI’s annual analysis of itsdatabase, which was last updated at the end of 2014.

Focusing a study on the accounts of consistent participantsallows for a “more meaningful analysis of the potential for 401(k)participants to accumulate retirement assets over time,” accordingto a release from the EBRI.