NEW YORK: Consumers travelling on packed subway trains are about twice as likely to make a mobile purchase compared to those on non-crowded trains, a new academic study has revealed.

The report, called "Mobile Crowdsensing", was conducted by researchers from the New York University Stern School of Business, Temple University and Sichuan University in Chengdu, China.

The researchers worked with an unnamed major Asian telecom provider, which monitored users in transit while texting them promotions.

The telecom provider's data also pinpointed how many mobile users were on a train at any given time, and the research showed that users responded more to mobile promotions as the number of passengers increased.

Specifically, the research found purchase rates measured 2.1% when a train had a density of two people per square metre, but this rose to 4.3% when the crowd density increased to five people per square metre.

This increased engagement with mobile devices was consistent during peak and off-peak times as well as on weekdays and weekends.

Professor Anindya Ghose, co-director of Stern's Center for Business Analytics, said this type of "mobile immersion" was caused by a psychological need to cope with the loss of personal space on crowded trains and that the findings could be of benefit for marketers.

"Our research suggests that crowding on trains is a unique marketing environment in which mobile promotions are seen as welcome relief," he said.

However, he told the Wall Street Journal that the effectiveness of mobile ads could decline if commuters found themselves packed-in "like sardines", as they often can be on trains in cities like Tokyo.

Data sourced from NYU Stern, Wall Street Journal; additional content by Warc staff