The influence of network structure and prosocial cultural norms on charitable giving: A multilevel analysis of Movember’s fundraising campaigns in 24 countries

•We study the interplay of network structure and countries’ prosocial norms on charitable giving.•We analyze Twitter and donation data from the 2013 Movember fundraising campaign in 24 countries.•Campaign network decentralization and size increase average donations amount.•Prosocial norms did not affect the effects of size and centralization on average donation amount.•Prosocial norms did affect the relationship between density and average donation amount.