A fast-ferry study that shows major financial and employment benefits for Rochester is based on optimistic ridership numbers, according to economics professors at local colleges, says the story “Analysts say ferry estimates too high” in the Sept. 17 Democrat and Chronicle. The economic analysis — commissioned by the private company starting the service and released last month — says a ferry could bring 1,320 new jobs to the city and generate about $46 million in tourist spending here in its first year. The study is based on an estimate of 1 million Canadians using the ferry annually — that would be 2,739 Canadians a day. “Is that realistic or not? I have my doubts,” said Thomas Drennan, assistant professor of economics. Drennen is the author of more than 20 publications that were produced in collaboration with various colleagues including “Who Will Fuel China?,” “The Kyoto Protocol and International Trade: the Carbon Loophole,” “Solar Power and Climate Change Policy in Developing Countries,” and “Agricultural Dimensions of Global Climate Change.” He holds a Ph.D. in resource economics from Cornell University, a master's degree in public affairs from the University of Minnesota, and a bachelor of science degree in nuclear engineering from Massachusetts Institute of Technology.