On the disclosure of ticket sales in charitable lotteries

•We study the effect of disclosure of ticket sales on revenue in charitable lotteries.•A policy of disclosing ticket sales in a fundraising lottery increases revenue.•The optimal timing of disclosure is when half of the players have purchased tickets.

We show that a policy of disclosing the ticket sales during a fundraising lottery raises total revenue when there are more than two bettors. The optimal timing of the disclosure is when about half of the players have purchased lottery tickets.