Q. An academic friend does not use a space following a comma,as this demonstrates. Is this “acceptable” or common? Certainly I can’t see that usage in CMOS.
A. We admire the economy of such a habit, but we can’t endorse it. Not that there isn’t a precedent for such usage. As recently as the nineteenth century, spaces before commas were common, at least in French. Guide pratique du compositeur d’imprimerie, a manual on typesetting by the printer Théotiste Lefèvre that was first published in 1855, reveals as much in a footnote that appears in a section on English composition:
That first line of text (in a detail from page 182) says that in English practice there’s no space between a comma (“virgule” in French) and the word that it’s next to (i.e., the word that it follows). Footnote number 3 steps in to allow M. Lefèvre to observe that not only is this unfortunate (“vicieux” is as bad as it sounds), but worse, it’s happening more and more in French works.
In Lefèvre’s book, space appears before commas, with two exceptions: (a) where the line of type is too crowded to allow for any and (b) next to r’s, v’s, and y’s. The latter were exempt, “parce que ces trois lettres portent un blanc suffisamment fort par en bas” (i.e., those three letters already leave enough space along the baseline; see Lefèvre, p. 30).
Go back even earlier in time, and the practice was to remove the space after the comma also—à la your academic friend—but only to accommodate very tight lines of justified text. In English, such commas with no space before or after can be seen in the earliest printings of the King James Bible (1611). This same usage could be seen at about the same time in Spanish in the novel Don Quixote (1605 for the first volume).
Back to the present: nobody puts spaces before commas in published prose anymore, and there are only two common scenarios in which the space after the comma is customarily omitted: next to a closing quotation mark, “like this,” and between digits in numbers like 1,132.