Most trade interventions will reduce, not enhance, national welfare. Start with skepticism about the ability of government to sort through the complex arguments to identify the particular cases in which an intervention will be helpful. Second, it is better to base trade policy on data than on stories. That is true even though, as Roger Noll has said, data is simply the plural form of anecdote . Problems with most data are well known.
Data are often wrong.
More damning for policymakers, data are not accessible to ordinary members of the public in the same way that anecdotes are. Anecdotes are readily understood, which is why politicians and trial lawyers and ministers all use them. Further, many of the anecdotes are compelling stories, telling, for example, about the raconteur's potential loss of a job that has been a lifetime investment if imports are not restrained or about the opportunity for adding jobs, for expanding the work force, if an export market can be opened to their products. Those stories are told with great sincerity, but each captures only a small piece of a much larger puzzle, and other stories are unlikely to fill in the missing pieces. Even bad data tend to give a more complete picture on which to base policy.