While 'essential' public services such as police and fire protection are provided in virtually every city, 'optional' public services, such as museums or stadiums, are often found in larger cities. By using a simplified urban land use theory model, this paper examines why optional public services are offered and why cities organize to jointly provide these services. Results suggest that optional public services are provided when their cost is 'small' relative to the cost of essential public services. An expansion of the model suggests that when optional public services are jointly provided, cities vary in size as model parameters vary.
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