21. He developed a body of new econometric tools that address these issues. 22. He also helped introduce econometric modeling to government economic planning and accounting. 23. This assumption is considered inappropriate for a predominantly nonexperimental science like econometrics . 24. In both cases, the authors offered supporting econometric evidence. 25. The main statistical method in econometrics is multivariable regression analysis. 26. Today, Cournot's work is recognized in econometrics . 27. Mossin was elected fellow of the Econometric Society in 1973. 28. The Journal of Financial Econometrics has an exclusive focus on financial econometrics. 29. The Journal of Financial Econometrics has an exclusive focus on financial econometrics . 30. It is conceptually one of the simplest inequality indices used in econometrics .