Giving investment bankers sweets and sending them a personalised email from the chief executive more than triples the chances of them donating a day’s salary to charity, according to a report published yesterday.

The research was published in a free report, published yesterday by the Behavioural Insights Team, known as the Nudge Unit, a social purpose company which was formerly part of the Cabinet Office, but now jointly owned by the government, innovation charity Nesta, and its employees.

The research, entitled Behavioural Insights Team Update 2013-15, showed the results of a “number of interventions” designed to get investment bankers to donate a day’s worth of their salary to charity.

Research was conducted with 6,175 bankers, and found that a combination of a packet of sweets and a personalised email from a charity chief executive made 17 per cent of those surveyed donate, compared to 5 per cent in the control sample.

A personalised email on its own resulted in 12 per cent of bankers donating, while sweets alone resulted in 11 per cent. A visit from a celebrity saw 7 per cent donate.

In an attempt to measure the effects of “repeatedly using the same interventions on people”, the investment bank trial was revisited a year later.

Those who had been given sweets the previous year, received them again, as did half of those who hadn’t received sweets the year before, for a comparison. Donations by those who received sweets the first time more than tripled from 3.1 per cent to 9.7 per cent, as in the first trial, yet donations fell by half in those who received sweets a second time.

The survey was first published by BIT in May in a separate report, entitled Applying Behavioural insights to Charitable Giving.