The Lima school district last week saw inarguable evidence that the state's voucher program is working. Fewer pupils applied for EdChoice vouchers to pay for a private school education instead of going to the city schools.Wait. Fewer pupils leaving the Lima school district via vouchers means that the state voucher program is working? Yes, it absolutely means that.No one intended the state voucher program to continually stock private schools with new pupils and the state money that comes along with them. Rather, vouchers were intended to let families escape failing schools — and to force those schools to bring up their standards.That's what has happened in Lima. Twenty-eighty fewer pupils applied for EdChoice scholarships for next school year than applied the previous year — about a 10 percent drop. The last day to apply was a week ago Friday. Assistant Superintendent Jill Ackerman credits changes the Lima school district has made for the decrease in EdChoice requests— two kindergarten through eighth-grade magnet programs and two middle schools, among other changes. One has to wonder how many of those changes would have come about — at least as quickly as they did — without the additional pressure vouchers put on school districts. Since 2006, parents in Ohio have had a way to move their children out of failing schools or failing school districts without having to move their residences. Proponents of the state voucher program, including us, believe that such competition for students gives public schools no choice but to improve or to keep losing students.Two things have happened in the Lima school district since parents began being able to use vouchers to move their children from failing schools. First, the district implemented a number of far-reaching changes to improve. Second, fewer parents opted to move their children. Those two things are related. School vouchers work.