Institutions matter for economic development and growth. By institutions I mean the formal and informal (pdf) rules that facilitate the interaction among individuals in a community. We know that institutions are a fundamental cause of long-run growth.
The theory of the day says:
Playing board games such as monopoly teaches children from an early age the importance of playing by the rules. Therefore, rules are more respected in countries where board games are (more) popular.
[This can be an idea for a social entrepreneur. It can be tested by having Monopoly sales, by country, as an independent variable, and an index of governance, like the world governance indicator, as the dependent variable]. [And that is my theory for the day :)][My mom thinks it is the best theory ever].