EAST LANSING, Mich., April 16 (UPI) -- Countries that are best at preparing their math teachers share several key conditions generally lacking in the United States, researchers say.

The first international study of what teacher preparation programs are able to accomplish found that in countries such as Taiwan and Singapore future math teachers are better prepared because students get rigorous math instruction in high school, university teacher-preparation programs are highly selective and demanding, and prospective math teachers are finding the profession attractive, with excellent pay, benefits and security.

"Some critics of teacher education believe you can bypass colleges of education and prepare teachers in an easier, faster way, but our study doesn't support that," Maria Teresa Tatto, an education professor at Michigan State University, which led the study, said in a university release Monday.

"In Taiwan, for example, nobody graduates without the demonstrated ability to teach mathematics," she said. "Here in the United States, far too many of our graduates lack the knowledge of mathematics and how to teach it, which they will need as they begin to teach."

The researchers analyzed data from representative national samples that included about 500 higher education institutions in 17 countries that prepare primary and secondary school teachers.

Taiwan and Singapore were best in preparing math teachers, and Russia also scored highly, the researchers said.

Poland, Switzerland and Germany did well, partly because they rely more on specialist teachers in lower grades, they said.

The United States generally finished below this group but above other countries that scored well below the international average, Tatto said.