Sentence:  Raymond Vernon reports that residents of East St. Louis have been driving across the Mississippi , through the heart of downtown St. Louis and out to the western suburbs for major shopping , simply because parking is easier at the big branches than it <WSD>is</WSD> in the heart of town . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)