Since Andrea is receiving a full scholarship for her undergrad degree, she is now thinking about going to graduate school. If she decides to pursue her PhD, she must go to school in the first period for her undergrad at zero cost, and attend PhD in the second period, also with zero cost. With a PhD, Andrea can make $90,000 a year. Will Andrea pursue her PhD? (Hint: You only need to compare college and PhD payoffs.) Since her payoff as an undergrad won't change, we only need to calculate her return for getting a PhD.