The author concludes that the best way to increase the blood supply in the city of Pulaski is to encourage more donations by people who are regular blood donors. This is based on a study conducted in two other cities, which showed that officials had a lot of success in convincing regular blood donors to donate more frequently. But it was difficult to attract first-time blood donors.

The author assumes that the city of Pulaski is relevantly similar to the other cities with respect to potential for the cities’ blood donors to increase the frequency of their donation. The author also assumes that there aren’t other ways to increase blood supply besides increasing blood donation frequency or getting first-time donors. (This overlooks the possibility of getting blood from other cities or countries or other sources.)