Until the early part of the twentieth century, practically all physicians in the United States and elsewhere were primary care physicians, not specialists. This changed dramatically in all developed countries over the remainder of that century, so that at present, over 75% of all American doctors specialize in fields like surgery, cardiology, dermatology, urology, and oncology. Specialization in Europe also grew over time, but at a much slower rate than in the United States, the result being that European medicine is practiced with relatively fewer specialists compared to generalists.
The growth in medical specialists over time is largely explained by the general economic theory of specialization and the division of labor. Medical specialization becomes more attractive when spending on medical care increases since a bigger market for medical care provides even highly specialized physicians a large enough market for their services. This conclusion is an application of Adam Smith’s famous dictum in the Wealth of Nations that the division of labor is influenced by the extent of the market. Since medical spending per person and in the aggregate is much higher in the United States than other countries, it is no surprise that American specialization is much greater than elsewhere.
The great advances in medical knowledge, especially since the 1950s, also contributed to the growth in specialization. For it takes expensive and very time-consuming investments by young doctors as medical residents and in other ways to gain command of the extensive information needed to practice modern surgery, oncology, cardiology, and other specialties. Specialization also increases when the ability to coordinate different specialists and generalists improves. That has been happening in the medical field with the growth of online records that transfers information among different specialists and generalists who are caring for the same patients, and especially with the development of group practices and medical centers that enable patients to visit different specialists and generalists in the same suite of offices or in nearby buildings.
Levels of compensation, as determined by the forces of supply and demand filtered through government policies and private insurance companies, also determine the degree and types of specialization. For medical students respond to the financial returns and other conditions found in different specialties and in general medical practice. In one important respect at least, as Posner indicates, the health care changes enacted into law by Obama will increase the demand for primary care physicians by providing subsidized medical insurance for over 30 million generally younger persons who have been without medical insurance. Young people primarily use medical care to treat the flu and other respiratory diseases, to receive general medical checkups, to treat the effects of accidents, and to get help on other medical problems that mainly involve visits, at least initially, to primary care physicians. However, the further growth over time in spending on the elderly through Medicare and private insurance will primarily increase the demand for cardiologists, oncologists, surgeons, and specialists in geriatric medicine.
Is there a “shortage” of primary care physicians relative to “shortages” of specialists? I am doubtful for several reasons. Many specialists also engage in general medical practice, especially among patients who initially come to them for specialized treatment, but who then receive medical care for medical problems that are the main business of general practitioners. This ability of specialists to also practice general medicine enables specialists to fill out their working days, and also tends to prevent any excess demand for primary care physicians from getting too large relative to the demand for specialists.
If this conclusion is correct, waiting times to get appointments for visits to general practitioners should not be significantly longer than the waiting times to get appointments to specialists. A 2009 survey by Merritt Hawkins, a healthcare consulting company, estimates willingness to take Medicaid patients and also waiting times in 15 metropolitan areas for cardiologists, dermatologists, orthopedic surgeons, obstetricians/gynecologists, and family practitioners. Willingness of general practitioners to take Medicaid patients is not lower than that of these specialists, with the exception of cardiologists.
While waiting times vary greatly among these areas, they are not systematically longer for family medicine than for the specialties surveyed. Waiting times are much longer for the Boston area than in any other area perhaps because of the vast expansion in health coverage in Massachusetts during the past decade. The wait times averaged over all the metropolitan areas vary by category of medical practice, from 16 days in cardiology to 28 days in obstetrics/gynecology. Family practice is in the middle at about 20 days. There appears to be a tendency for the categories with generally more urgent needs, like cardiology, to have the shortest waits, and those with the least urgent needs, like dermatology and obstetrics, to have the longest waits.
Much more evidence is needed on both wait times and salaries to reach definitive conclusions about shortages in different medical markets. However, these waiting time data suggest that substitution on the part of patients between family practitioners and specialists who can offer similar services, and arbitrage among medical students in deciding which fields to enter, prevents the development of particularly large “shortage” of general practice physicians.