The betting markets are all betting based on whether the US with announce that it's in a recession (I think), which probably has different (lower) odds than actually being in a recession. It at least makes sense that it's different, but that's a huge difference.

I guess it's kinda like betting on who will win an election vs. betting on a candidate conceding an election. The odds aren't necessarily the same, even though they're (on paper) closely related events.