New York City's charter schools are making strides in closing achievement gaps between disadvantaged inner-city students and their better-off suburban counterparts, a new study concludes. The study, conducted by Stanford University researcher Caroline M. Hoxby and her co-authors Sonali Mararka and Jenny Kang, is based on eight years of data for students applying to the city's growing number of charter schools. The study finds that attending charters from kindergarten to 8th grade can help close city-suburban test score gap.