Explain as fully as possible the Duranton and Puga model. Be sure to address: 1. What is the source of agglomeration economies in the model? 2. Show the consumer's utility and demand function. 3. Graph an individual firm's pricing and output decisions. How many firms are there in each city? 4. What is the role of transportation costs in the model? How do they influence land rents? Show this graphically. 5. What is the significance of the assumption that goods are not tradable between cities? 6. What is the significance of the assumption that inputs are unshared between industrial sectors? 7. How can the model be extended to include the role of infrastructure investment? Include a graph of the results. 8. How could the model be extended to include inter-industry agglomeration economies? Include a graph of the results