The business deals that cleaned up Times Square began during the Koch administration prior to Rudy coming into office. Interestingly, it actually began in Bryant Park -- the park behind the library on 42nd and Sixth. The park, which was once home to drug dealers, etc. was cleaned up by putting in a number of legit businesses that attracted local office workers. The good drove out the bad.
I think you have your facts wrong, it didn't begin with the Koch Administration and Union Square, Koch watched as Rome burned for one thing and for another it was Dave Dinkins who was in power when Bryant Park began a revitalization project overseen by the Rockefeller institute not the city. Furthermore, it was Rudy Giuliani who single handedly led the campaign to clean up the city. No other mayor enforced the decency laws, rezoned, policed and then let market forces take over as did he. It is a matter of record. If you don't believe me, contact the ACLU, he had them in a tizzy in his efforts to re zone the area, after all the ACLU gets big bucks from mob porn purveyors and they (the mob) hated Guiliani. You think Koch did that? You must be a lib. thttp://www.city-journal.org/html/9_4_the_unexpected.