[Shawn]

MSA usually makes the most sense, but there are exceptions.

San Francisco-San Jose being separate MSAs doesn't make sense (even though I understand the technical reason for it).

Worcester being in a separate MSA from Boston doesn't make any sense, especially when Rockingham and Hampshire Counties in New Hampshire are in the Boston MSA. It's also hard to separate Bristol County, Mass from the Boston MSA and place it entirely in the Providence MSA, given that Bristol County's northern edge in Easton is all of 19 miles south of Boston's Hyde Park. I get that it's a stretch to think of Boston and Providence as a truly single metro, but their borders are less than 30 linear miles apart; picking which suburb is Boston's most southern and which is Providence's most northern is really hard. I grew up in Foxboro, which is exactly halfway between the two on I-95, and I still don't know where you'd put the border. Realistically you'd need to split Bristol and Norfolk Counties up, and the Census doesn't do that for MSAs or CSAs. Regardless, splitting Worcester into its own MSA is weird.