More resources, a financial sector and a real world market.
Resources:
Simply put...more resources. More products to manufature from more natural resources. Certain manufactured products or natural resources required to create or obtain other resources.
Market:
A stock market, players capable of investing in businesses. Capability of players to incorporate companies to raise capital, etc. Players create names for their businesses. (i.e. - Tom's Food Store)
Finance:
Capability of players and incorporated companies (organizations of players) to perform financial services to other players. (Lending, Brokering, Insurance, etc..).