The study looked at how national fiscal rules affect government spending on public investments. They analyzed data from 35 countries between 1995 and 2015. The findings show that rules on spending have a negative impact on government investment, especially in economic areas. Rules on budget balance also have an effect, but it's less clear. The study suggests that while relaxing fiscal rules won't fix the problem of underinvestment, having well-designed rules can help protect public assets to some extent.