Source: ETH Gas Station (EDIT: or the other table for a breakdown).

This doesn't mean that transactions with a gas price that low are guaranteed to go through, though: the miners in question may change their setting back up if the situation changes.

However, what it does show is that some folk are keeping their hand on the pulse.

EDIT: "Signalling" should have been "accepting".

EDIT2: For an interpretation on what an economically rational gas price could be, see this comment in a 2-month old topic.

It also has links to a detailed model on the Ethereum Foundation blog, and a summary page with an API endpoint.

Can't remember if that model took into account the delay incurred by pools (as compared to solo miners) due to an additional network hop from actual raw metal workers to the pool broadcaster. Might just be the reason why pools have to set a gas price above the "baseline rational".