Why did the Democratic caucus results come in more quickly than the GOP results?

Possibly because of the way the voting is counted. For the Republicans, its one person, one vote, with each vote being counted.

The Democrats vote in groups, which could make the vote counting quicker. Since, as far as I understand it, the voting is done in small groups by hand count? Not sure about this, but it would make the vote counting quicker.

EDIT: To the fool beneath me. There were TWICE as many Democrat votes in Iowa than Republican.

The popular vote was much larger for the Republicans than Democrats. That is if when you click on Iowa on the map below and Yahoo is reporting correctly.

I'll give you the REAL answer. Do you want to spend hours of a day with the Democrat process?

People are lazy and don't want to spend their whole day dealing with that mess. So less Democrats vote in Iowa and there are less votes to count and add.

Caucus's are more efficient than primaries, especially if your crew has their stuff together. The Democrats were more organized than the Republicans in Iowa this time around.

The Democrats use a statistical estimating procedure while the GOP uses actual headcounts, thus they took longer to report.

Fewer democrats participate??

They started half an hour earlier.