1.1. Suppose that a researcher is trying to determine whether jogging is good for a person's health. She examines this question in two ways. In method A, she examines whether joggers live longer than nonjoggers. In method B, she examines whether jogging reduces cholesterol in the bloodstream and lowers blood pres sure; then she asks whether lower cholesterol and blood pressure prolong life. Which of these two meth- ods will produce reduced-form evidence and which will produce structural model evidence?