ALBANY, N.Y. — A city in New York state has found a novel way of motivating residents to pay their back taxes: personal notes handwritten by city officials.

The idea stemmed from an experiment on late-tax payments, in which the city of Syracuse partnered with researchers at Syracuse University. City officials wrote and signed thousands of notes by hand, rather than sending standard legal letters demanding payment.

The result was the city collecting nearly $1.5 million more than it predicted traditional methods alone would have brought in. University researchers estimate that the personal approach brought in 57 percent more revenue from delinquent property owners than the city could expect from using more traditional letters.

The notes took a less threatening approach, focusing on steps the resident could take to avoid late penalties or legal action. Instead of being addressed “dear property owner,” the notes were all personally addressed to the resident. Each had a brief, handwritten message on the outside of the envelope as well, researchers said.

“It’s the kind of positive outcome that occurs when you aren’t afraid to try something new,” Syracuse Mayor Ben Walsh said.

Collecting late taxes is a challenge for cities, which often use computer-generated letters to residents threatening action if the money isn’t paid. The researchers said the experiment could have broad applications to a number of government services.

“These are small, simple changes that can have huge payoffs,” said Leonard Lopoo, a Syracuse professor and director and co-founder of Maxwell X Lab, a behavioral research center at Syracuse University’s Maxwell School.

The lab’s managing director, Joe Boskovski, said treating people as humans can yield results.