My recommendation for an Economic Development Intern interview is to get familiar with the Town of Sahuarita. I suggest looking over the basic demographics of the city to better understand. Population, median household income, school rating, etc...
I also recommend looking into the history of the Town and how it's grown throughout the years (which is a lot). Look into the major previous, current and future projects in the pipeline.
The Town of Sahuarita really suffered when Freeport McMoran laid of hundreds of their employees. I recommend learning about that and researching how they were able to combat those issues.
Make sure to express how your gained knowledge through your program can benefit them and how become valuable to them.