LinkedIn secretly experimented on 20 million users in job-mobility test

The LinkedIn app on iOS  (Carl Court/Getty Images)
The LinkedIn app on iOS (Carl Court/Getty Images)

Do you feel like job hunting on LinkedIn got harder in recent years? It might not completely be your fault, because you might have been part of social experiments run by the company.

According to a recently published study, LinkedIn ran experiments on more than 20 million user accounts worldwide from 2015 to 2019, with the aim to improve people’s experience on the platform and help more people get more jobs.

However, that might have backfired for some users, according to the study’s results.

The experiments saw LinkedIn randomly vary the number of weak and strong connections it suggested to people via its People You May Know algorithm, which pushes new connections to users.

LinkedIn ran the tests based on the “strength of weak ties” sociology theory, which posits that people are more likely to get jobs through weak ties, or acquaintances, than through strong ones.

That means some people might have missed out on job opportunities because they weren’t recommended as many weak connections as others, while they were part of the experiments.

The effects, while seemingly minor, generated big differences for those on the winning end: after a year from their first connection, people who had received more recommendations to connect with “weak” contacts were twice as likely to score jobs at those contacts’ companies, compared to those that connected more with “strong” contacts.

In fact, researchers from LinkedIn, M.I.T, Stanford, and Harvard Business School agreed that “the weakest ties had the greatest impact on job mobility, whereas the strongest ties had the least”, based on their findings from analysing the data.

LinkedIn as an engine of job mobility

While LinkedIn didn’t specify where the accounts experimented on were based, according to its user base, the platform counts 33 million users in the UK as of April 2022, out of a global total of 850 million. That means 3.8 per cent, or 760,000, of users in the study might have been British.

The researchers further found that moderately weak ties (as measured by mutual connections) and the weakest ties (as measured by interaction intensity) “created the most job mobility”.

However, researchers also found that this varied by industry. Workers in digital industries, such as software engineering, saw more job mobility through weak ties, but for less digital industries, strong ties actually helped people get more jobs.

This makes sense, as workers in less digital industries are less likely to be on LinkedIn in the first place. Creative industries are also infamous for their nepotism problem, with the Arts Council writing that “if you’re not from a privileged background, you’re even less likely to succeed”.

Good intentions, mixed results

Sinan Aral, lead author of the study, told the New York Times that LinkedIn’s intention was to refine its algorithm to improve everyone’s job prospects, “rather than anointing some people to have social mobility and others to not”.

The experiments don’t appear to have violated any of LinkedIn’s policies, even though most users probably were not aware they were being experimented on.

These experiments, called A/B tests in tech lingo, are common among tech firms, which use them to try out different versions of their products to find those that resonate best with users.

But some experts have questioned whether the scale and impact of LinkedIn’s study goes beyond simple A/B testing.

Michael Zimmer, an associate professor of computer science and the director of the Center for Data, Ethics, and Society at Marquette University, told the New York Times that the findings pointed to some users receiving a notable leg-up in the job-hunting process.

“These are the kind of long-term consequences that need to be contemplated when we think of the ethics of engaging in this kind of big-data research,” he added.