Then why do you make this quip? It reads as if you are only including it to sow doubt about the claim by association. Maybe I'm overly cynical, if so I apologize.
> The rise of international trade, which depressed agricultural prices in comparatively unproductive Europe, was another huge one.
The idea that productivity of Europe was challenged by international trade was/is also wildly popular with Marxist historians - the rise of well-developed international capitalism as a pre-requisite to reaching the productivity levels required for a socialist revolution to be successful is a key part of Marx ideas. The rising competition from increasingly efficient US agriculture and industrialization was even explicitly called out for its effects on Europe in at least one of the prefaces Marx and Engels wrote to translations of the Communist Manifesto.