I'm curious how much the effect is causal vs correlational. That is are students that sign up for certificates more likely to finish (because maybe they feel li

I'm curious how much the effect is causal vs correlational. That is are students that sign up for certificates more likely to finish (because maybe they feel like they've already paid and don't want to waste it) or are students that are more likely to finish more likely to sign up for certificates in the first place? I would guess both effects are present but I'd like to know how it breaks down.