Nearly half of the value delivered by advisor’s is emotional, according to new research.

Advisors have long maintained that much of their value is delivered outside a client’s investment portfolio, but have lacked clear ways to quantify those impacts they have on client’s lives, according to “Assessing the Value of Advice,” a new paper published today by Vanguard.

“Our results highlight the need for a broader advisory industry investment in value metrics,” wrote the report’s authors. “These metrics will have to extend beyond traditional portfolio outcomes to encompass broader financial goal attainment and emotional well-being.”

Vanguard analyzed the impact of financial advice among more than 100,000 participants in its $140 billion AUM Vanguard Personal Advisor Services, a hybrid robo-advisor that offers live financial planners to clients engaging in digital advice.

Vanguard defined the value of advice along three  dimensions: portfolio, financial and emotional.

Vanguard measured the impact of advice on portfolio outcomes by studying changes in portfolio diversification among 45,000 clients who had switched from self-directed investing to using an advisor. This research revealed that financial advice usually alters the amount of equity risk for two-thirds of investors: 32% of the study participants had their equity allocation increased by 10% or more, while 34% had equity allocations decreased.

Engaging with an advisor changed the allocation to international investments for 90% of the account holders and reduced cash holdings for 28%. In fact, among the study participants, the average percentage of portfolio holdings in cash dropped from 16% to 1% in the year between six months before the adoption of face-to-face financial advice and six months afterwards.

Single-stock risk was “effectively eliminated” for the 10% of investors who had significant positions in single stocks, and about 80% of investors saw an increased allocation to portfolios based on index funds, substantially reducing their investment costs.

For financial outcomes, Vanguard examined whether 105,000 investors who had established a retirement goal were on track using a probabilistic model. Most clients engaging with Vanguard’s Personal Advisor Services had a good chance of achieving their stated retirement goals.

According to the paper, 80% of the clients with a defined retirement goal had an 80% chance of reaching that goal, while 20% had goals incongruent with their projected levels of retirement resources. Vanguard noticed that these results were highly skewed. The average investor had an 86% chance of achieving their retirement goals.

Vanguard translated these results as a possible indication that many clients over-prepare for retirement and have made unnecessary sacrifices in their pre-retirement lifestyles—“living more modestly than they actually need to,” as the report put it.

In emotional outcomes, Vanguard attempted to estimate the fraction of an advisor’s value that came from emotional elements like trust, connection to the advisor, peace of mind and behavioral coaching.

According to a survey of 504 Personal Advisor Services clients, as much as 45% of the total value of an advisory relationship perceived by investors is derived from emotional elements, while the remaining 55% is derived from functional aspects of the relationship like portfolio management and financial planning.

Looking more deeply at the emotional implications of financial advice, clients are deriving the most value from having a relationship with a trusted expert – approximately 55% of the emotional value comes from the mere presence of the advisor-client relationship. Another 28% of the value stems from the protection and assurance that advisors offer, and 7% from planning-related concepts.

When asked about the relative importance of certain expressions of emotional value, the Personal Advisor Services clients ranked trust in their advisor, the monitoring and updating of their financial plan, and the feeling that they are on track to meet their goals as the most important.