The phrase "a large contributing factor" is correct and usable in written English.
It can be used when discussing elements that significantly influence or play a role in a particular outcome or situation.
Example: "The lack of funding was a large contributing factor to the project's failure."
Alternatives: "a significant influence" or "a major determinant".
Since depression is a large contributing factor to suicide, they controlled for that variable throughout the study.
Ohio has been hit hard by the decline in manufacturing jobs, but the rising price of gasoline and heating oil is also a large contributing factor.
A large contributing factor is how I earn my living.
More so, the fact that there are more women than ever in politics is a large contributing factor to Congress addressing how sexual harassment is dealt with on Capitol Hill.
It is becoming more and more apparent that the migrant pull to Mumbai for work is a large contributing factor to the unyielding growth of this community at the macro-level.
But why don't we recognize that a large contributing factor to this epidemic is lack of sleep?
However, in areas with more abundant land, area expansion was a larger contributing factor.
Data quality may be a larger contributing factor for (3) due to the larger detector distance employed during data collection.
Accidents due to movement of strata in underground coal mines had been a major concern for the mining industry and it is largest contributing factor of underground coal mine accidents.
According to one study, the largest contributing factor to uncertainty about vaccinations was a "conspiratorial mindset".
In a 2009 column, Thomas Friedman approvingly quotes a former business executive, who argues, "Our education failure is the largest contributing factor to the decline of the American worker's global competitiveness, particularly at the middle and bottom ranges".
