VOA [notes](https://www.voanews.com/usa/us-politics/could-tbilisi-decide-iowa-caucuses-2020-us-presidential-race) that 

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> In the past, the downside of the time-consuming caucus process has been lower voter turnout. In the 2016 Iowa caucuses only 15.7% of the voting population participated. In contrast, more than 50% of New Hampshire voters cast ballots in the 2016 primary. 
> 
> 
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Is this (large) difference in participation consistently observed for other caucuses vs primaries in the US?