An economist is building a model to understand the effect of a new public transportation system on traffic congestion in a city. One proposed model includes only two factors: the number of public transit users and the number of cars on the road. A second, more complex model includes these two factors plus average household income, fuel prices, local business density, and road quality.

Analyze the potential advantages and disadvantages of using the simpler model versus the more complex model for this specific purpose. In your analysis, explain the trade-offs an economist must consider when deciding how much detail to include in a model.