New York Mayor Michael Bloomberg has announced the opening of 54 new schools planned for the fall, many of which will be located in building vacated by schools closed on grounds of poor performance.

“Students and parents deserve top-quality school choices, and we’re going to continue to ensure that they have even more of them,” the mayor said at a news conference, which was held in the library of Washington Irving High School, one of the schools being closed.

This will bring the total of new schools opened by the Bloomberg administration to 589 since 2002 while they’ve closed 140 schools. This policy has been criticized by some mayoral candidates hoping to take over his position when he leaves office next year.

While the new schools are often cost effective by sharing space in the buildings vacated by failed schools, and tend to have higher graduation rates and exam results than the school they replace, teachers unions argue the success is an illusion based on them having to contend with fewer problems of poverty and special needs.

However, the mayor and the schools chancellor, Dennis M. Walcott, pushed back sharply against that argument on Tuesday.

“The student bodies of these new schools mirror those of the schools they replace,” the mayor said, “with similar percentages of black and Latino students, English-language learners and students with disabilities.”

Edcuation department data would appear to back Walcott’s position, showing that the new schools had a higher percentage of black and Latino and disabled students than their predecessors while catering to a similar number of English language learners.

So while criticisms of Bloomberg’s results on his new school policy seem to be without merit so far, union candidates still smarting from pension cutbacks and the release of teacher evaluation data are likely to continue the anti-Bloomberg rhetoric in the hopes of election.

William C. Thompson Jr., the former comptroller and a 2009 Democratic candidate for mayor, called the closing of schools a “shell game” and a “Ponzi scheme,” and urged the State Legislature to issue a moratorium on such closings.