Harry J Holzer 
Unemployment, Vacancies and Local Labor Markets [PDF ebook] 

Unemployment rates in the U.S. vary considerably over time and across local areas. Economists have long been concerned with explaining these variations and have attempted to distinguish various components of unemployment to explain these variations in rates. Holzer uses firm-level data on job vacancies, sales growth, and wages within and across a group of 28 local labor markets to examine these issues.