A Tale in the Desert is probably the closest I know of. Its player base is limited compared to most MMOs (around 1000-2000ish, last I looked), but it's a comba

A Tale in the Desert is probably the closest I know of. Its player base is limited compared to most MMOs (around 1000-2000ish, last I looked), but it's a combat free game centered around economic production. It's also a bit unusual in that it has no in game currency. The last time I played (a bit more than 5 years ago), it was largely a barter economy. However, there was a player run item exchange whose credit functioned as a defacto currency. I have no idea what the current state of the game is, but if you're curious about a non-combat economic MMO, it's worth taking a look at.