"conclusive cause" is correct and usable in written English.
You can use it when you need to refer to a cause that is definitive and without a doubt accepted as the source of an effect. For example, "The conclusive cause of the car accident was the driver's reckless behavior."
It's that science has failed to demonstrate a conclusive cause.
Then a government pathologist says there is no conclusive cause of death.
A post-mortem exam last week failed to establish a conclusive cause of death.
Federal investigators said on Thursday that they had not yet found any conclusive cause for the crash, in which a tourist from Australia was killed and two other passengers were seriously injured.
An international autopsy team looking into the death of Floribert Chebeya, a prominent human rights activist in the Democratic Republic of Congo, reported Thursday that it was unable to give a conclusive cause of death.
That information came from a preliminary necropsy, but it was not a conclusive cause of the sudden death of the 6-day-old female cub, who was heard grunting just 17 minutes before she was found lifeless, zoo officials said.
It's impossible to establish a conclusive cause-and-effect relationship, but the finding is at least suggestive of the fact that economies populated by those whose wealth is self-made are more dynamic than those that rely on the perpetuation of existing economic elites and their descendants.
In this sense, no conclusive cause-effect relationship can be drawn from our study.
"While that's not a conclusive cause-and-effect connection (there's a lot more wealth in Silicon Valley besides Facebook stock), the rising real estate prices do indicate that something big is happening.
Similar phenomena have been observed before, but the difficulties associated in uncoupling anthocyanin production with morphological alterations in their packaging prevented to draw conclusive cause-consequence relationships.
Incompatibility and difference in conclusive force cause defeat among arguments.
