Final answer:
The drop in world aluminum prices leads to an increase in structural unemployment in Pittsburgh, which can be alleviated by establishing employment agencies and improving job matching on job-search websites, not by taxing job search activities.
Step-by-step explanation:
When examining types of unemployment in different scenarios, we categorize them into cyclical, frictional, or structural. In the case of sectoral shifts like the world price of aluminum falling, the demand for labor among aluminum-producing firms in Pittsburgh would decrease, while demand for labor among airplane manufacturing firms in Washington would increase. The unemployment that results from such sectoral shifts is best categorized as structural unemployment.
To reduce structural unemployment, policies that do not include taxing job search activities but rather improve job search efficiency and assistance would be helpful. Therefore, establishing government-run employment agencies (Option B) and improving a job-search website to match workers with job vacancies more effectively (Option C) would help achieve this goal.
Frictional unemployment is different from structural unemployment. It occurs as a natural part of the job search process when workers move between jobs or enter the labor market. The level of frictional unemployment will depend on the ease of learning about job opportunities and the willingness to move to new areas for work.