Only two things have been proven to increase voter participation (in the USA):
Peer pressure, culture of voting (your neighbors noticing they didn't see you at the poll site).
Competitive races.
On the flip, there are many things which counteract vote suppression:
Universal, automatic voter registration (just like all other mature democracies).
Reenfranchise felons.
Fair redistricting.
Adequate funding for election administration.
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I've not seen any data suggesting that digital voting schemes have or may boost voter participation. And there's numerous cases where such systems disenfranchised voters.
Peer pressure, culture of voting (your neighbors noticing they didn't see you at the poll site).
Competitive races.
On the flip, there are many things which counteract vote suppression:
Universal, automatic voter registration (just like all other mature democracies).
Reenfranchise felons.
Fair redistricting.
Adequate funding for election administration.
--
I've not seen any data suggesting that digital voting schemes have or may boost voter participation. And there's numerous cases where such systems disenfranchised voters.