title: Data from a professional society placement service as a measure of the employment market for physicians.
abstract: OBJECTIVE
  To determine whether data from a professional society placement service--the Professional Bureau of the American College of Radiology--are a valid measure of the employment market.
  
  
  METHODS
  For the United States from 1990 to 1998, the authors compared three placement service measures-the annual number of job listings, job seekers, and listings per seeker-with two presumably valid measures of the employment market-annual total jobs available (which was ascertained from surveys of hiring) and radiologist median income relative to the all-physician median. For the comparisons, both graphic displays of the data and correlation were used.
  
  
  RESULTS
  In graphs, patterns of change were similar. The correlation of job listings, which measure demand, with total jobs, which also measure demand, was 0.84 (P =.04). The correlation of (a) job seekers, a measure of supply, and (b) listings per seeker, which involve both supply and demand, with total jobs was substantial but lower: 0.58 (P =.23) and 0.76 (P =.08), respectively. Correlation of the three placement service measures with relative income, which presumably depends on both supply and demand, was 0.80-0.88 (P <.05 for each measure).
  
  
  CONCLUSIONS
  The statistical significance levels of the correlations and the pattern of findings--namely, stronger correlations among measures of the same aspect of the employment market--indicate that these placement service data are valid and reasonably accurate measures of the employment market.
authors.affiliation: Research Department, American College of Radiology, 1891 Preston White Dr, Reston, VA 20191, USA. jonathans@acr.org
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Sunshine
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Lewis
authors.forename: Barbara
authors.initials: B
authors.lastname: Schepps
authors.forename: Howard P
authors.initials: HP
authors.lastname: Forman
mesh_terms: D004651:Employment; D007182:Income; D011871:Radiology; D012955:Societies, Medical; D014481:United States; D000078329:Workforce