Credit: Zhen Hu


Behavioral Science

MIT Sloan study finds paramedic teams comprised of multiple partners outperform teams based on familiarity


CAMBRIDGE, Mass., Jan. 28, 2020 – In many operational settings, like in-flight hospitality, police patrols, and paramedic services, teams are assembled for short collaborations and then disbanded. An important question is whether it is better to have stable teams with high familiarity or to expose workers to multiple partners. A recent study by MIT Sloan School of Management Prof. Jónas Jónasson addresses this question and finds that while there are benefits to both types of teams, those exposed to multiple partners generally are more beneficial.  

“Prior literature hypothesizes benefits for both types of teams, but this is the first study to analyze which one is more beneficial,” says Jónasson. “Our setting allows us to study a spectrum of worker profiles -- from those with stable partners and high team familiarity to those with very frequent partner changes. If you look at the extremes of this spectrum, we find that exposure to multiple partners outweighs the benefits of team familiarity.”

Jónasson and his colleagues looked at 2011 data on ambulance transports from the London Ambulance Service involving new paramedic recruits. Ambulance transports are typically staffed by stable teams of two paramedics. However, new recruits are scheduled on a relief roster and therefore assigned to partners based on administrative convenience. This results in exogenous variation in partner assignments, by which some new recruits have stable long-term partnerships and others get exposed to multiple partners.

The researchers measured the impact of team familiarity and exposure to multiple partners on operational performance. They found that the impact of being exposed to multiple partners depended on the type of process at hand.

For less standardized tasks, such as patient pickup at the scene, where paramedics need to make decisions and think creatively in the moment, they saw a “strong and immediate” positive effect for teams exposed to multiple partners.

Specifically, they saw that a two standard deviation increase in the multiple partner exposure of a new recruit results in his crew spending on average 7.3% less time (2.2 minutes relative to an average of 30.5 minutes).  “This is likely to have a significant impact on patient outcomes for approximately 20% of the transports in our data that were classified as life threatening,” he says.

However, this effect was moderated for more standardized processes, such as patient handover at the hospital. “The paramedics who are newer tend to go through the entire protocol with the hospital staff, whereas more experienced paramedics have the experience to focus on the most important aspects and get to the point faster,” he explains, noting that the effects on both types of tasks are amplified during periods of high workloads.

“These results suggest that for non-standardized tasks – those that don’t come with a manual – managers should not blindly favor or adhere to a high-team familiarity strategy because there is value in exposing workers to multiple partners. You need to observe someone more experienced to learn how to do a job, so there is value in working with different partners,” he says.

For standardized tasks where workers can rely on operating procedures as a guide, there is still value for new partners to work together. “If you want workers to develop the skills to outperform the procedural guide, then exposing them to multiple partners is a way to make that happen,” says Jónasson.

He adds, “Overall, inducing high team familiarity by keeping team membership intact can limit workers’ opportunities to acquire useful knowledge and alternative practices from exposure to a broader set of partners. Our analysis shows that managers should consider scheduling strategies that favor exposure to multiple partners over ones based on team familiarity.”

Jónasson is the coauthor of “Learning for many: Partner exposure and team familiarity in fluid teams,” published by INFORMS. His coauthors include Zeynep Aksin of the Koc University, Sarang Deo of the Indian School of Business, and Kamalini Ramdas of the London Business School.

The MIT Sloan School of Management

The MIT Sloan School of Management is where smart, independent leaders come together to solve problems, create new organizations, and improve the world. Learn more at

For more info Patricia Favreau Associate Director (617) 895-6025