this is what i found and it is for age 1, im not sure if it is the same for age 2

In an Academy, you primarily spend Gold to research particular technologies. If you have a second city, it will need an Academy of the same level to "share" the already completed technologies.
Construction Research is the one exception. The time reduction from Construction will apply to all cities, regardless of their Academy status.
http://www.theevonywiki.com/Academy