In defense of neither, let me offer an explanation of what is happening grammatically in the phrase "shop local." For lack of a better term, I shall call this morphing of words.

As an example, consider the search engine Google. Google was a name created for a company. As a name, it is a proper noun. However, when you want to search for something on the Internet, you say, "Let's google it." The noun has morphed into a verb.

The word "local" is an adjective (example, local news, local berries, etc.). However, in the phrase "shop local," local is a direct object of the verb "shop." Since by definition a direct object is either a noun or a pronoun, local is morphed from an adjective into a noun.

The message in this explanation is that American English language is amorphic. What is taken as standard today is a mere quaint memory tomorrow. Grammar linguistics lesson for the day concluded.

Bruce Bevan

Pinehurst