Please DO NOT answer this question if you use British English. You might help by answering the other question I posted just before this one.
I have found examples suggesting there is a fundamental difference in the way the Oxford and Merriam-Webster dictionaries handle the punctuation of compound adjectives AFTER NOUNS.
I live in a small city in Indonesia and cannot go to a library to research this myself.
My understanding has always been that writers should always hyphenate (or not) compound adjectives after nouns in the same way as the expression is listed in their preferred dictionary.
That is not how CMOS does it with this example. The Merriam-Webster Dictionary (the one CMOS uses) defines the adjectival form of 'middle-class' with a hyphen. Yet CMOS at 7.85 states this is correct:
the neighborhood is middle class
Can anyone describe a process to follow when writing in American English to determine whether a compound adjective after a noun needs to be hyphenated?