People from one neighborhood buy or sell goods and services to the other. Advertising, word of mouth, or tradition might entice new visitors. Supply and demand are roughly balanced, or the market is adaptable enough to cope when they aren't.

• Who pays whom, and for what?
• Who benefits from the arrangement? Who suffers?
• Who would like a piece of the action?

People from one neighborhood in the dynamic buy or sell goods and services to the other. Market prices are volatile, or there may be an imbalance in supply vs. demand.

• Who gains from the instability? Who loses?
• Where else can supply, demand, or labor be found instead?
• How are people coping?