NORTHAMPTON — A disproportionate number of Northampton parents who send their children to area charter schools are affluent and well-educated, according to a recent survey.

The findings come during a heated debate over whether Massachusetts residents should vote in November to lift the state cap on charter schools. The Massachusetts Charter Public School Association has pushed the issue, which calls for the addition of 12 more charter schools per year anywhere in the state. But opponents say more charters would starve public schools of taxpayer dollars.

John Provost, superintendent of Northampton Public Schools, said the survey raises questions about equity that voters should take into consideration.

Results of the survey, which was conducted by the Abacus Associates in conjunction with the superintendent’s office, found that 6 percent of families surveyed have a household income of under $50,000 per year while 43 percent have an income of $100,000 or more.

Additionally, of the 78 households with 113 children polled, college graduate is the lowest level of education among parents, and 79 percent of the families contain at least one parent with a graduate degree.

Provost found the results surprising, he said. Although the survey could not be completed for parents of public school children, he said the charter school demographic it revealed was not representative of Northampton families as a whole, or, to the best of his knowledge, of families in Northampton Public Schools.

“I understand the charter school movement as intending to provide high-quality options for students who are trapped in low-performing districts because of family income,” Provost said.

“That’s not what we’re finding is happening with the families in the charter schools serving our area, or at least the families from Northampton who are choosing our charter schools.”

The four charter schools addressed in the survey are Hilltown Cooperative Charter Public School in Easthampton, Pioneer Valley Chinese Immersion Charter School in Hadley, Pioneer Valley Performing Arts Charter Public School in South Hadley and Four Rivers Charter Public School in Greenfield.