Thread by @Usherwood

Since we're thinking about Brexit endgames, let's just remind ourselves of how two-level games work:

For those of you who missed that particular class, 2-level games were introduced as an idea by Putnam in the late 1980s to help describe international negotiations (jstor.org/stable/2706785)

In essence, negotiators have to work two negotiations simultaneously: with their international interlocutors and with their domestic 'colleagues'

What each level will accept thus impacts on what is negotiable at the other level. So if your domestic constraints are tight, then you have to be less flexible internationally

That might mean you're able to get more of what you've been bound to ask for, but it might also mean there's more chance that this doesn't overlap with what your international counterparts want/will accept

(really, stop me if any of this sounds familiar)

Part of this is also down to BATNAs. If either level has (or feels it has) a viable alternative to a negotiated outcome, then that also reduces the changes of a negotiated outcome occurring.

Of course, no-deal outcome (perceptions of) costs will be unevenly spread. So it's also important to know which actors with which powers to shape win-sets see what costs

As you add in more issues, than usually the smaller the size of a win-set, as more preferences/red lines come into play.

However, if you can keep those issues quite discrete, then you can use them as side-payments, so increasing the chances of a successful deal

But as Putnam notes, those side-payments matter most when they help tip a swing voter over the line into supporting the deal, so they need to be focused and specific, rather than general and across-the-board

That suggests working for a headline deal, gauging points of (domestic) opposition, then working up side-payments to get sufficient support

(which is basically where we're at right now IMHO)

We might close by noting Putnam's comments about the rather thankless task of being that chief negotiator, caught between levels:

(Level II is the domestic one)

I'll leave you to decide which of these May is prioritising

tl;dr two-level games are particularly tricky, with lots of scope of blockages