What about the October 2015 liability shift? If grocery stores "still haven't rolled out Chip & PIN support", then they face liability for counterfeit and lost or stolen cards. Issuers can conditionally allow fallback transactions [1], do you know if issuers are generally denying fallback transactions? Is the prompt "this card has a chip, please insert and wait" for a swipe on a card with a chip due to the merchant's policy to avoid the liability shift, or is it due to the issuer denying fallback?
The liability shift only matters if the potential loss outweighs the cost of running all transactions as credit until your issuing bank and hardware support the US Common Debit AID is greater than the potential fraud liability.
For a grocery store <1% per transaction and 3% per transaction is a pretty huge difference, one of my local stores that only takes debit cards still doesn't support chip cards because of the madness with the US Common Debit AID preventing them from enabling the EMV support on their terminals.
[1] http://www.emv-connection.com/downloads/2015/05/EMF-Liabilit...