how long to wait before nudging invited conference participant?

[rabbitandfox23]

Hi! I'm running my first conference, planned a year from now. Most of the invited participants have responded to my invitations but some are still outstanding.  How long do you generally wait before a gentle nudge?

[Parasaurolophus]

I think it's a function of how much time you need to budget to recruit their replacements, how often you're likely to need to iterate that process, and how desperate you are for that particular person to participate. If you're really desperate, then wait longer. Otherwise, a month seems like a generous amount of time before you prod. Then maybe another three weeks before you move on?

[Hegemony]

I would guess that no answer means they're not interested, so nudge them after 3-4 weeks so you can cross them off the list and move on.

[Katrina Gulliver]

Yes comes right away, no never comes.
Follow up after 2 weeks (there's a chance your original message just got swept to the bottom of their inbox by a tsunami of student messages), then if you still hear nothing, move on to someone else.