"studied the impact" is grammatically correct and can be used in written English.
For example, "The research team studied the impact of rising sea levels on coastal communities."
Their view, however, is not shared by most educationalists who have studied the impact of grammar schools.
Like these institutes, our group has studied the impact of carbon tax policies.
Michelle Budig, a professor at the University of Massachusetts-Amherst, studied the impact that becoming a parent had on earnings.
The OECD has recently studied the impact of trade "exposure" on incomes per person in several countries.
They studied the impact of two predators, feral cats and kiore, or Pacific rats, on a small burrowing seabird, Cook's petrel.
In 2000 she was a Fulbright scholar in Cotonou, Benin, where she studied the impact of international aid on the education of girls.
Dr Nhan established the free OGCDC, having studied the impact of Agent Orange as a student, to match Vietnamese families to foreign private financial donors.
We studied the impact of progestin dose on this risk.
Two groups working independently studied the impact, and their findings are in strong agreement.
A large amount of empirical research has studied the impact on unemployment and employment.
Leonard (1977) studied the impact of fertilisation on stream water draining Pumice soils in Kaingaroa Forest.
