Study: Weak Ties, Strong Employment Value

New research confirms the high value of distant connections on LinkedIn and other social media employment platforms

By Paula Klein

Your mom was right when she told you to call that friend of her friend’s son about a new job — and now there’s data to prove it.

According to a new study conducted by researchers from MIT, Harvard, Stanford, and LinkedIn, published today in Science, it is exactly this type of “weak tie” relationship that often yields the best results for online job searchers. The research is important to employers and policymakers who can benefit by optimizing the digital labor platforms that are proliferating in the global economy.

The Strength of Weak Ties is one of the most influential social theories of the last 50 years, but until now no comprehensive experimental causal tests of this theory existed as it relates to employment,” says MIT Sloan School of Management Professor Sinan Aral, who was on the research team. The theory, proposed by University of Chicago Professor Mark Granovetter in 1973, maintains that infrequent, arms-length relationships are more beneficial for employment opportunities, promotions, and wages than strong ties. In other words, weak ties can be your strongest allies.

Granovetter argued that weak ties provide more access to novel information because they connect people to diverse parts of the human social network, reaching across economic, demographic and industry strata. But he lacked the hard data to prove the causal effects.

The just-released research is the largest experimental study to date on social media’s impact on the labor market. It backs up the original proposal with five years of study data and analysis from the world’s largest professional social network. The results show that weaker social connections — not your closest peers — have a greater beneficial effect on job mobility. “We present large-scale, longitudinal, experimental evidence on the causal effects of strong and weak ties on job mobility,” says MIT PhD graduate Karthik Rajkumar. The paper, “A Causal Test of the Strength of Weak Ties,” was published by Science September 15. In addition to Aral and Rajkumar, the other researcher paper authors include recent MIT PhD graduate Guillaume Saint-Jacques, Stanford Professor Erik Brynjolfsson, and Harvard Business School Professor, Iavor Bojinov.

MIT Sloan Professor Sinan Aral explaining social networks.

Five Years, 20 Million People Studied

The team conducted a five-year set of experiments on LinkedIn with 20 million people around the world, during which approximately 2 billion new ties and 600,000 jobs changes were recorded, according to an analysis of the research also published in Science. As noted by Saint-Jacques: “We used data from large-scale randomized experiments conducted on LinkedIn’s “People You May Know” (PYMK) algorithm to test the weak tie theory and its impact on the labor market.”

The study verifies that whether LinkedIn’s PYMK algorithm recommends more weak or more strong ties could make the difference in someone getting their next job.

“It’s not a matter of ‘the weaker the better’ or ‘the stronger the worse,’ ” explains Bojinov of Harvard. “Our results show that the greatest job mobility comes from moderately weak ties — social connections between the very weakest ties and ties of average relationship strength.”

The results are significant to policymakers studying the labor force as well as social media and platform companies looking to sharpen their AI algorithms. “It is incredibly important that we understand how the algorithms used by digital platforms like LinkedIn impact the labor market, employment rates, and the broader health of the global economy,” Brynjolfsson said.

Strong Online Impact

Aral, who is also Director of the MIT Initiative on the Digital Economy, noted that 40 million people search for employment every week on LinkedIn, and three people are hired on the platform every minute, creating tremendous impact on the economy.

“More than ever, people are using social media platforms to find jobs, search for better jobs or to switch industries entirely,” Aral said.

For employers and job applicants the study highlights the importance of actively managing social networks to ensure they are as broad as possible. In an economy increasingly dependent on social networks, we need to consider ‘friends of friends’ and online recommendations as serious paths to better jobs, talent pools, and even as labor trend indicators. “Weak ties on social networks can be an extremely useful part of managing your career, promotions, advancement, and even wages,” Aral adds.

Just like mom always said!



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