New York City has been cheated out of $340 million in education aid generated by lottery ticket sales over the past four years, a new report by Assemblyman Scott Stringer found.

Mr. Stringer found that between 2000 and 2004, city residents purchased 44% of lottery tickets statewide but that city public schools received only 38.8% of the total statewide lottery education aid.

That 5.2-percentage-point discrepancy adds up to a lot of money. In the first year, New York City lost out on $48.4 million. That total grew to $57.7 million the next year, and then to $91.3 million. Last year, the city was cheated out of $142.4 million, Mr. Stringer said.

“This is a gross example of New York City generating this revenue and not getting the proceeds back,” Mr. Stringer, a Democrat of Manhattan, said.

Mr. Stringer said constituents ask him all the time how much money the lottery generates and where the money goes.

“It’s been a big mystery to people,” he said. “I want people to know it’s not all going where they think it’s going.”

He said that the state could fix the formula so that the city receives its fair share immediately, before lawmakers figure out a solution to the Campaign for Fiscal Equity education-funding dispute. The state has been found to be insufficiently funding New York City schools.

Mr. Stringer has introduced legislation under which the Lottery Education Fund would track the sales of lottery tickets by school district and then distribute the funds proportionally, so each district would get the same proportion of funds it generates in ticket sales.

A spokesman for the Division of Budget in Albany, Peter Constantakes, said that when Governor Pataki first came into office the city had 37.4% of students, yet received only 34% of total state education aid. Under Mr. Pataki’s leadership, he said, the tables flipped, with New York City now having 36.5% of the students and receiving 38.3% of state education aid.

He said 60% of the money in the governor’s new “Sound Basic Education Fund” would go to the city. That adds up to an additional $195.65 million a year.

“The current formula has been in place for more than 10 years,” Mr. Constantakes said, referring to the lottery aid formula. “Despite the Assembly’s failure to enact legislation to change this formula, Governor Pataki has made great strides in increasing the city’s share of the state’s education dollars, and today New York City receives a greater share of state school aid than the city’s share of students.”

A New York City education official who did not want to be named said Mr. Stringer’s findings were not shocking, and that the city has long been getting an inequitable share of state aid.