Is there any research on the impact of mail-in voting on turnout?

[Renew Deal]

I ask because it's clear the republicans know its bad for them. I've seen the abstract "if everyone votes we win" comments. But are there any facts on the impacts on turnout and the impacts by party?

[BlueTsunami2018]

1. Here's an article on it.

It seems to increase turnout, in some places dramatically.

https://www.google.com/amp/s/www.washingtonpost.com/outlook/letting-people-vote-at-home-increases-voter-turnout-heres-proof/2018/01/26/d637b9d2-017a-11e8-bb03-722769454f82_story.html%3foutputType=amp

[msongs]

2. down this year in all blue hawaii from 4 yrs ago but....virus nt

[pecosbob]

3. They got an 80% turnout rate in Utah last cycle with mail-in voting

People actually vote more if they can do it without having to show up in person.