From The Economist's article on the US's economic troubles:
American states and cities typically offer their employees defined-benefit pensions based on years of service and final salary.
The Oxford Dictionary defines "salary" as a count noun. Singular count nouns call for the use of an article.
Is the use of the zero article before "final salary" here explained by the fact that the noun is a part of a list-like structure ("service and final salary") where "service" cannot take an article as a mass noun (hence no article before either)?
I wonder how to explain that in linguistic terms; haven't found a mention of such cases in R. Quirk's grammar so far.