I read the report from your attached link. I am not a research expert, but I notice some questionable parts of the essay.
1. As LovingLife123 said, I agree with her, the metro city has saturated nurse market, while rural area has more demand than supply. It is simple and easy understanding because it is the fact that more people want to go to rich area and have their life. But look at the data in the report, California and Massachusetts (high salary state) have shortage, while Maine (where I am at; I see nurses moving away from Maine. Few want to stay) has large surplus. It seems not logical.
2. At the remark of the table, it states, "Notes: The model assumes increased insurance coverage associated with Medicaid expansion and insurance marketplaces, together with year 2014 health care use and delivery patterns. Numbers may not sum to totals due to rounding.
a The projections assume that each state's supply and demand are equal in 2014. "
I am not sure about this research has considered Medicaid future development or not. But mathematically, if the researcher "assume" 2014 supply and demand are equal, that table already has bias results. The researcher did not have evidences about the 2014 equal supply and demand. We should not use the 2030 result because it is based on assumption.