Global GDP as defined and used by Ourworldindata: WorldinData.org, https://ourworldindata.org/grapher/world-gdp-over-the-last-two-millennia)

All years after the year this happens will resolve to YES, e.g. if it happens in 2031, then 2035, 2040 etc will all resolve in YES.

Disclaimers:

1. This question is part of Foresight’s 2023 Vision Weekends to help spark discussion amongst participants, so the phrasing and resolution criteria may be vaguer than I would normally like for this site. Apologies for that. We thought it would still be useful to make the market public to potentially inform other discussions.

2. If you would to add alternative answers, please do so in the comments!