What could explain the gap between the United States and the euro zone with regard to labour productivity? Employers' capabilities

Labour productivity is higher and is increasing faster in the United States than in the euro zone. What could explain this difference? Not the human capital of employees (labour force skills), which is similar in the United States and the euro zone; Not the transformation of the employment structure from manufacturing industry to services, which is also powerful in the United States; Not the weight of the new-technology sector, which is not significantly higher in the United States. The only remaining explanation is therefore the "human capital" of employers, due to far higher corporate investment (overall and in new technologies) and innovation in the United States than in the euro zone.