Environmentalist: The use of snowmobiles in the vast park north of Milville creates unacceptable levels of air pollution and should be banned  Milville business spokesperson: Snowmobiling brings many out-of-towners to Milville in winter months, to the great financial benefit of many local residents  So, economics dictate that we put up with the pollution
Environmentalist: I disagree: A great many cross-country skiers are now kept from visiting Milville by the noise and pollution that snowmobiles generate
Challenging an assumption that certain desirable outcome can derive from only one set of circumstances