So it seems to me that there are a lot of confounding factors here. Do we actually know what causes GDP/hour to go up and down? It doesn't seem directly related to vacation time.
It seems to me more like the Wikipedia article you linked to is saying "countries that give a lot of vacation to all citizens can still have a high GDP per hour worked" and we don't understand what other confounding factors can contribute to GDP/hour
Yeah, as another data point, Japan, South Korea, Singapore, and Hong Kong are way below the US on the GDP-per-work-hour metric. Yet if you've ever been exposed to office life in any of them, you'd know that their work/life balance is far more tilted toward work than the US. You'll also notice that they have less per-hour GDP than countries with more statutorily mandated paid leave. I don't think we can really glean anything from this chart as to the effects that vacation time has on productivity.
So it seems to me that there are a lot of confounding factors here. Do we actually know what causes GDP/hour to go up and down? It doesn't seem directly related to vacation time.
It seems to me more like the Wikipedia article you linked to is saying "countries that give a lot of vacation to all citizens can still have a high GDP per hour worked" and we don't understand what other confounding factors can contribute to GDP/hour