Oh, great! And the prediction market did not beat polls (it tied with them on swing states and beat them on safe states, as I speculated).

I guess between this and the other commenter who made money betting 538's model on predictit, I consider this pretty thoroughly debunked.

You can’t do the analysis on PredictIt, they limit market size heavily.

Do you know of any similar sites that don't limit bet size?

I saw some sports betting sites were offering odds, but not really a true market like predictit I think

Betfair seems to offer most of the same contracts as PredictIt as two-sided markets with lower fees and no cap on bet size or number of participants.

They are geolocked for some features, however

PredictIt also appears to have this issue. I must proxy my traffic through my US VPS to use it.

augur

I still kinda feel like the market beat the polls. Kinda.

In order to interpret the polls, you need top statisticians with lots of domain knowledge. In order to interpret the betting market, you simply read the odds and are done.

If you went to the market and you bet that the polls would be correct, you made money.

The particular market available to US residents has separate issues about "reading the odds" where events that strictly contain other events are often priced multiple pennies cheaper, the total number of expected presidents is often ~1.1, events with probability at least 0.9 are almost always underpriced, often by a nickel or more, etc.