How to get a job often comes down to one elite personal asset, and many people still don't realize it

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The old adage "it's not what you know, it's who you know" has perhaps never been more true.

Today, some estimates suggest that up to 70% of all jobs are not published on publicly available job search sites, and research has long shown that anywhere from half to upwards of 80% of jobs are filled through networking. Looking ahead to a dramatically shifting labor market, the worth of networks only stands to grow. According to experts at Deloitte's Future of Work practice, tomorrow's job seekers will increasingly need to "find others who can help them get better faster — small workgroups, organizations, and broader and more diverse social networks."

Unfortunately, the value of these networks is routinely and egregiously underestimated when it comes to helping young people get ahead. Efforts to increase social mobility and access to opportunity rightfully focus on what people know and the credentials they obtain — their human capital. But that model is incomplete. It undervalues the array of professional connections into industry that young people need to compete — their social capital.

Unequal networks start early

From the zip code a child is born into, to the postsecondary education institution (or lack thereof) that she attends, to her first (and second, and third) job, every experience an individual has impacts the professional connections within her reach.

Young people inherit unequal networks into the knowledge economy: those whose parents have a bachelor's degree or more are far more likely to know individuals working as CEOs, lawyers, and the like. And as income inequality grows, these gaps in access to a wide range of working adults stands to increase. Today, children from wealthy families are enjoying a boon in spending on enrichment activities that in turn increases their access to informal mentors, a fancy term for adults like coaches, tutors, and leaders encountered through everyday life. Young adults from the top socioeconomic quartile report nearly double the number of nonfamilial adults in their lives as their peers from the bottom quartile.

"Networks unlock valuable advice, insights, and influence that can either exacerbate existing social strata, or be powerful levers for equity and opportunity. It's time to shift to the latter."

These gaps shape young people's later career plans and prospects. The majority of postsecondary students report turning to their informal social networks for college major and career advice.

The professional networking company LinkedIn, whose CEO Jeff Weiner has been especially vocal about these disparities, has dubbed this the "network gap." The network gap refers to the advantage some people have over others in accessing opportunity based on where they grew up, where they went to school, and where they work. In fact, according to LinkedIn's own data, people who are referred for a job are a whopping nine times more likely to get it.

The good news is that professionals are increasingly recognizing that sharing their network is a powerful tool for promoting social mobility. And new initiatives and tools are making it easier than ever to do so.

On the national Mentoring Connector database, you can find -- in just a few clicks -- a host of quality-vetted opportunities to mentor young people in your region. And with new technologies on the rise, if formal, in-person mentoring models are out of reach, you can also lend your social capital online. To provide career-specific know-how, you can join the Seattle-based nonprofit Educurious's expert network. Educurious offers project-based courses in which experts work with students through video chat to discuss real-world problems together. Or you can participate in the internship platform Parker Dewey's Gigs for Good initiative, aimed at opening up short-term job opportunities (and in turn, expanding professional networks) for students from underrepresented backgrounds. You can also take a page from LinkedIn's "Plus One Pledge," which encourages the networking giant's users to share their time, experience, and networks with people who lack access to the connections they need to get the jobs they want.

The result of network sharing is powerful, with impacts that can last a decade or more. According to a recent Brookings study on the factors associated with higher quality jobs among 29-year-olds from disadvantaged backgrounds, early internships and mentoring were a key ingredient to blazing pathways to economic security. These experiences, the authors found, marked the chance for young people to forge positive relationships with adults as supervisors and mentors. Describing these relationships, they pointed out that it was "notable that they affect job quality a decade later, given that the effects of training programs sometimes fade over time."

Chances are, no matter how hard you've worked on your own, there were people in your life who opened new doors, gave personal advice, took bets on you, wrote letters of recommendation, or offered words of encouragement. Networks unlock valuable advice, insights, and influence that can either exacerbate existing social strata, or be powerful levers for equity and opportunity. It's time to shift to the latter.

—By Julia Freeland Fisher, author of "Who You Know: Unlocking Innovations that Expand Students' Networks" and director of education research at the Clayton Christensen Institute.

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