Yes, education vouchers are economical and efficient, because education vouchers are ultimately cost effective. Vouchers allow people to use market forces to find better education for their children. Public education is notoriously inefficient. Although it might seem like vouchers take money away from public schools, in the end, public schools will perform more efficiently under the pressure of competition.
Education vouchers are just another attempt to privatize schools, which is a horrible idea, but it makes a lot of capitalist money so of course they promote it. If you look at all the countries with the most successful educational systems, they have public schools, teachers unions, massive public investment and spending in education, etc.