Since New York City represents the largest single school district in the state, large changes in its pupil count can significantly affect not only the state aid it receives but also have profound effects on the amount of money the state distributes in aid. This research study was designed to measure the probable impact of the removal of nonattendees from the districts' active membership count. The 989 schools in New York City were broken down into four types by educational level, and through a stratified random selection process, 107 were included in the sample. Teachers' registers in those schools were analyzed for the month of January to determine ratios of nonattendees to pupil membership counts. A nonattendee was defined as a pupil who had not attended school for the past 30 days. The sample survey reveals that there were an estimated 30,813 nonattendees in New York City in 1977-78. New York City received an estimated $620 per pupil for that period. The loss to New York City, if state aid were paid on the basis of pupil membership rather than on average daily attendance weighted in accordance with the weightings in effect for that period, would be $23,873,720. (Author/MLF)