In another study of physicians’ labor supply that was not restricted to young physicians, Douglas M Brown found the labor supply price elasticity for primary care physicians to be close to zero and that of specialists to be negative, at about −0.3 Thus, for this sample of physicians, increases in wages have little or no effect on the amount the primary care doctors work, while a 10% increase in wages for specialists reduces their quantity of labor supplied by about 3% Because the earnings of specialists exceed those of primary care doctors, this elasticity differential also makes sense Sources: David M Blau, “The Supply of Child Care Labor,” Journal of Labor Economics 11:2 (April 1993): 324–347; David M Brown, “The Rising Cost of Physician’s Services: A Correction and Extension on Supply,” Review of Economics and Statistics 76 (2) (May 1994): 389–393; John P Burkett, “The Labor Supply of Nurses and Nursing Assistants in the United States,”Eastern Economic Journal 31(4) (Fall 2005): 585–599; John A Rizzo and Paul Blumenthal “Physician Labor Supply: Do Income Effects Matter?” Journal of Health Economics 13:4 (December 1994): 433–453 ANSWER TO TRY IT! PROBLEM While at a point in time the supply of people with degrees in computer science is very price inelastic, over time the elasticity should rise That more students were majoring in computer science lends credence to this prediction As supply becomes more price elastic, salaries in this field should rise more slowly [1] Although close to zero in all cases, the significant and positive signs of income elasticity for marijuana, alcohol, and cocaine suggest that they are normal goods, but significant and negative signs, in the case of heroin, suggest that heroin is an inferior good; Saffer and Chaloupka (cited below) suggest the effects of income for all four substances might be affected by education.Sources: John A Tauras “Public Policy and Smoking Cessation Attributed to Libby Rittenberg and Timothy Tregarthen Saylor URL: http://www.saylor.org/books/ Saylor.org 278