Conventional wisdom points to a shortage of qualified teachers as the source of much of the out-of-field teaching assignments in America's public schools. However, recent studies of the Center for the Study of Teaching and Policy at the University of Washington show organizational issues within the schools are as much to blame as any shortage of qualified teachers." These studies conducted by Richard M. Ingersoll used data from the Schools and Staffing Survey conducted by the U.S. Department of Education's National Center for Educational Statistics. The study found factors such as class sizes, school hiring practices, recruitment and hiring strategies, and the quality of principal leadership all relate to the levels of out-of-field teaching in a school.

"While state certification requirements ensure basic preparation of newly hired teachers, there is little regulation of how teachers are employed and utilized once on the job. This lack of oversight allows school principals "an unusual degree of discretion" in the placement of teachers. Several examples of how this lack of oversight may lead to out-of-field placements were included in the reports. Some examples are as follows:

• Instead of finding a new teacher, a school principal may find it more convenient and cost-effective to assign a couple of teachers from other subjects to each 'cover' a section or two each.
• If a teacher leaves suddenly in the middle of the year, a principal may opt to hire on a substitute teacher permanently rather than institute a formal search. This substitute may not be fully qualified, but will probably be less expensive.
• When faced with the choice of hiring a fully qualified candidate or a less qualified candidate who is also willing to coach a major varsity sport, a principal may find it more expedient to choose the latter.
• Faced with the choice of hiring an unqualified candidate or doubling the class size of an existing class with a fully qualified teacher, some principals may opt for the smaller class size.