  Generative artificial intelligence (AI) presents large risks for society when
it is used to create fake news. A crucial factor for fake news to go viral on
social media is that users share such content. Here, we aim to shed light on
the sharing behavior of users across human-generated vs. AI-generated fake
news. Specifically, we study: (1) What is the perceived veracity of
human-generated fake news vs. AI-generated fake news? (2) What is the user's
willingness to share human-generated fake news vs. AI-generated fake news on
social media? (3) What socio-economic characteristics let users fall for
AI-generated fake news? To this end, we conducted a pre-registered, online
experiment with $N=$ 988 subjects and 20 fake news from the COVID-19 pandemic
generated by GPT-4 vs. humans. Our findings show that AI-generated fake news is
perceived as less accurate than human-generated fake news, but both tend to be
shared equally. Further, several socio-economic factors explain who falls for
AI-generated fake news.
