A recent question on EL&U asks Is it correct to use "how's" as short for "how does"? I have a series of tangentially related questions about a fairly common (in American English) phrase usually spelled as "how's about":
Does the spelling "how's about" make sense under normal conventions of punctuation, and (if so) is the "how's" component of the phrase a contraction or a possessive?
If "how's" is a contraction here, what words is it a contraction of?
If "how's" is a possessive here, how might we restate the underlying idea to indicate the possessive aspect of how, without including the apostrophe-s?
If the spelling "how's about" (with an apostrophe) doesn't make complete sense, is there a better way to spell it?
By way of background, I note that Robert L. Chapman & Barbara Ann Kipfer, Dictionary of American Slang, Third Edition (1996) offer the following entry on "how's about":
how's about prep phr by 1925 What do you feel or think about: How's about a drink? —Budd Schulberg
The first edition of this dictionary (1961) reported that "how's about" means "how about," suggesting that the apostrophe-s is simply an instance of proparalepsis (adding an extra syllable or letters to the end of a word). But even if we attribute the additional sound to proparalepsis, we have not yet explained why orthographically the spelling came out as "how's."
Not surprisingly, an Ngram Viewer graph of Google Books content shows "how's about" as being generally far more common than "hows about," "howsabout," and "howzabout"—three possible alternative spellings.