Betting markets are useful when politics is chaotic

Lively markets in political betting would be a gift today, since they have taken on a profound importance in the days since Joe Biden’s disastrous debate against Donald Trump. The question of whether Mr Biden should drop out is urgent; the answer influenced by his chances of beating Mr Trump. Polls, even fast ones, are slower than markets. And markets moved sharply against Mr Biden’s chances of continuing in the White House and being the Democrat nominee, before recovering a little in response to the president’s obstinacy (see chart).