Which cultural trait is most likely to influence the government and economics of a region?

Religion. Religion effects what products are sold (a Jewish or Islamic government will not sell pork in the marketplace.) In the Middle ages, the citizens of most European Countries thought that the King was chosen by God, so whatever that King issued was in essence the word of God. Religion also effects things like women's prominence in a community, the acceptance of diversity, and how a country views the ideas of warfare vs. pacifism.