특히 2단계 최소 자승법은 프로빗과 OLS 분석으로 이루어져 비교적 활용이 용이하여 압도적으로 많이 사용되었다.
In particular, the two-step least-squares method was used overwhelmingly. After all, it was relatively easy to use because it consists of probit and OLS analysis.