Journal Issue: Excellence in the Classroom Volume 17 Number 1 Spring 2007
The Supply Side of the Teacher Labor Market
It is somewhat misleading to speak of a national teacher labor market in America. In reality, the U.S. market is localized in such a way that teachers in one geographic region typically do not compete for jobs in another region. Thus, teacher shortages are often specific to certain regions or even to specific districts or schools within a region.
Another feature of teacher supply is the relatively high attrition rate among new teachers. Indeed, some researchers argue that so-called shortages result not so much from a paucity of licensed teachers as from a revolving door into and out of the profession.44 Using data from the nationally representative 1991–92 Teacher Follow-Up Survey (TFS), David Grissmer and Sheila Kirby found that the attrition rate for teachers with one to three years of experience is roughly 8 percent annually, compared with 4.5 percent for teachers with four to nine years of experience. 45 Using TFS data from 1989–90, 1991–92, and 1994–95, Ingersoll calculated that roughly one-third of new teachers leave the profession within three years of entry, and that almost half leave within five years.46 Neither of these estimates, however, considers the number of teachers who leave the classroom and later return. In the past, this “reserve pool” of licensed teachers who are not currently teaching has been an important source of supply when demand for teachers has risen.47
Teacher Supply: What Hasn’t Changed
The supply of teachers—the number of eligible (that is, traditionally, alternatively, or temporarily licensed) people willing to teach at a given wage—has always been a function of workforce demographics, salaries, opportunity costs, and working conditions.
Over the past forty years, the supply of teachers has varied by academic subject area.48 Supply has been less adequate relative to demand for teachers who have high opportunity costs—those trained in fields such as mathematics, computer science, chemistry, or physics—than for those trained in fields that have lower opportunity costs, such as the humanities.
Special education is another area in which the supply of teachers has often been inadequate. One reason may be that special education teachers work with students who face greater academic, and in some cases behavioral, challenges than other students. Furthermore, special education teachers must complete, update, and implement Independent Educational Plans (IEPs) for their students in order to comply with the Individuals with Disabilities in Education Act (IDEA). Thus, special education positions often entail more administrative responsibilities and paperwork than do general education positions. A national sample of principals surveyed in 1999–2000 reported difficulty staffing 75 percent of their special education openings and 77 percent of their mathematics openings, as against only 30 percent of social studies openings.49
There is considerable evidence that the supply of effective teachers is not equitably distributed across U.S. schools. A 2002 study by Hamilton Lankford, Susanna Loeb, and James Wyckoff found that New York State schools serving high concentrations of poor, nonwhite, or low-achieving children were disproportionately staffed by teachers who were inexperienced, were uncertified in subjects they taught, had graduated from noncompetitive colleges, or had failed their licensing examination on the first attempt. For instance, in schools with more than 20 percent of students scoring at the lowest proficiency level in fourth-grade English language arts in 2000, 35 percent of teachers had failed their licensing examination on the first try and 26 percent had degrees from noncompetitive colleges, as against only 9 percent and 10 percent of teachers, respectively, in the highest-scoring schools. The authors also found that roughly a third of this sorting occurred within districts where compensation differences did not play a role.50
The distribution problem is not confined to New York. National board certified teachers in North Carolina, for example, disproportionately work in suburban schools serving economically advantaged students.51 Also, throughout their schooling, African American students in North Carolina are especially likely to be taught by novice teachers.52 Along similar lines, a national study of the Teach for America (TFA) program found that non-TFA teachers working in socio-economically disadvantaged schools served by TFA were far less likely than the average U.S. teacher to have attended a selective college or to have completed student teaching before becoming a teacher.53 Just as the problem is not confined to one geographical area, it is not new. Howard Becker described it in the Chicago public schools as early as the 1950s, and it remains one of the most pressing challenges facing public education today.54
The likely explanation for why well-educated, experienced teachers tend to avoid working in schools serving high concentrations of low-income children or children of color is that working conditions in these schools are especially difficult. Many books by journalists support this proposition.55 But because few quantitative studies include direct measures of working conditions in schools serving different types of student populations, few data exist about which working conditions contribute to the distribution problem. One study based on the 1991–92 Teacher Follow- Up Survey does indicate that among teachers who transfer, those who transfer from urban high-poverty public schools are more likely than the broad population of such teachers to cite the following as reasons for their dissatisfaction: “student discipline problems” (29 versus 18 percent), “lack of faculty influence” (26 versus 13 percent), “lack of student motivation” (27 versus 10 percent), “interference in teaching” (12 versus 5 percent), and “lack of professional competence as colleagues” (23 versus 8 percent).56
Teachers’ preferences for working in areas close to or similar to those where they grew up also contribute to the distribution problem. Using New York State data from 1999 to 2002, Donald Boyd and colleagues found, for instance, that 61 percent of new teachers took jobs within fifteen miles of where they went to high school and that 85 percent stayed within forty miles of home.57 Because economically disadvantaged areas have fewer college graduates than more affluent areas do, they also have more trouble providing their own educators. Thus the lack of educational attainment in these areas becomes a self-sustaining cycle.
Late hiring in school districts serving many disadvantaged students also exacerbates the distribution problem. For example, a three-state survey of 374 new teachers showed that 28 percent of new teachers in low-income schools were hired after the start of the school year, compared with only 8 percent in high-income schools.58 The problem of late hiring in urban districts is explored more fully by Brian Jacob in his article in this volume.
One component of teacher supply that has received little research attention is substitute teachers—a group that, from the beginning of kindergarten to the end of grade twelve, teaches the typical American public school child for about two-thirds of a school year.59 Although the No Child Left Behind legislation required that all teachers become highly qualified by 2006, it explicitly excluded substitute teachers. In fact, nineteen states do not even require substitutes to hold a bachelor’s degree.60 Although some substitute teachers use these temporary jobs to gain entry into permanent positions, there is little research on the qualifications or skills of the substitute pool, whether these vary by type of school district, and what share of substitute teachers eventually moves into permanent teaching positions.61
Teacher Supply: What’s New
We now turn to a discussion of changes in the supply of teachers over the past two decades. Because the supply of teachers is a function of population demographics, salaries, opportunity costs, and working conditions, we examine how trends in each of these factors have affected teacher supply.
Demographics. The teacher workforce in the United States has aged steadily since the mid-1970s and is on the verge of a large wave of retirements. In 2005, 42 percent of teachers were aged fifty or older, compared with 25 percent in 1996. The distribution of teacher experience shows the same trend. In 2001, 38 percent of U.S. teachers had more than twenty years of experience—up from 28 percent in 1986 and 18 percent in 1971.62 The implication is that more teachers will be needed to replace the many who will retire soon.
In the past, two sources of supply have been important in responding to increased demand for teachers. One is the share of college students who train to become teachers, which has grown. The second is the reserve pool—licensed teachers who return to teaching after a period spent in another activity. Undoubtedly, both sources of supply will be important in responding to the increase in demand for teachers in the years ahead. But, as we show, several labor market developments have made it much harder for today’s schools to attract talented college graduates.
Salaries and Opportunity Costs. The supply of teachers in the labor market has been adversely affected by increasing labor market opportunities for women and minorities. Before the civil rights and women’s movements, opportunities for women and people of color were severely constrained by discrimination. As a result, among the available alternatives, teaching was a relatively high-status occupation for both women and people of color—a situation that helped guarantee a steady flow of academically talented women and minorities into the teaching profession. Changes in the occupational choices of black college graduates illustrate this trend. In the late 1960s, six out of every ten black college graduates entered teaching within five years of graduation; by the early 1980s, that figure was one in ten.63
As labor market opportunities for women and minorities have expanded, their opportunity costs have risen—and have risen most sharply for those with stronger academic abilities. Research by Sean Corcoran, William Evans, and Robert Schwab shows that from 1964 to 2000 the average ability level of entering female teachers declined only slightly, but the share of young female teachers from the top decile of their high school class fell from 20 percent to 11 percent.64 Figure 4, which is excerpted from their work, illustrates these trends.
In summary, improved labor market opportunities for women and minorities have forced education to compete increasingly with other occupations for talented college graduates. And as figure 4 indicates, education is losing this competition. Part of the explanation is that other occupations reward strong academic skills more than education does.65 Using data from the National Center for Education Statistics’ 1993–2003 Baccalaureate and Beyond Longitudinal Survey, Dan Goldhaber and Albert Liu found that unlike teaching salaries, nonteaching salaries for recent female college graduates rewarded college selectivity, technical majors, and high GPAs.66
Working Conditions. In the past two decades, teachers’ working conditions have improved in some ways and deteriorated in others. On the one hand, as noted, both class sizes and student-teacher ratios have fallen.67 On the other hand, NCLB and state accountability systems have increased pressure on teachers to improve student test scores. The pressure is particularly great on teachers working in schools that serve high shares of disadvantaged students. For instance, one 2004 study found that after the implementation of a statewide accountability system, teachers in North Carolina were more likely to leave schools with low test scores and those that were labeled “low-performing.”68
Another trend in working conditions is the movement to differentiate the traditionally flat teaching career. Historically, the main option for teachers who wanted to advance professionally was to stop teaching and become administrators.69 The 1980s saw efforts to create career ladders that would generate leadership opportunities for teachers. But many of these initiatives faltered because some teachers saw them as threats to the egalitarian nature of the profession.70 Today a similar trend toward differentiation of teaching roles appears to have two distinct rationales. One is the belief that peer-to-peer professional development will help teachers raise student achievement.71 The other is the belief that more opportunities for advancement will mitigate attrition among new teachers, some of whom report wanting upward job mobility.72 Among today’s new positions are mentors, who assist new teachers; peer coaches, who provide instructional guidance to colleagues; and peer reviewers, who evaluate their colleagues’ instruction.73 Little systematic data, however, exist on how widespread these roles are or whether they improve instruction or increase teacher retention.74
What’s True Internationally
In most countries, salaries, class size policies, curriculum requirements, and licensure standards are set at the national level; in the United States, they are set at local and state levels. Nevertheless, the problem of inequitable distribution of effective teachers across schools is not unique to the United States. For example, teacher surpluses in the north of England coexist with teacher shortages in more populous, diverse areas such as London and the southeast.75 Research in Norway has also shown that teachers are more likely to leave schools with high shares of minority or special needs students.76 The inequitable distribution of effective teachers poses a troubling challenge for policymakers worldwide—a challenge that may take on even greater proportions in industrialized nations as Europe continues to become more ethnically diverse.
International comparisons also reveal considerable variation in teachers’ working conditions, even among nations with strong systems of public education. In Singapore, whose students scored first among the fortynine nations that participated in the 2003 Trends in International Mathematics and Science Study (TIMSS), the central government prescribes the curriculum and places a heavy emphasis on students’ performance on standardized tests.77 In Finland, whose students scored first on the Program for International Student Assessment (PISA) in 2000 and 2003, teachers have high levels of curricular autonomy, and student assessments tend to be individualized and diagnostic.78 These differences in working conditions between nations with high-performing educational systems suggest the need for caution in thinking about the types of working conditions that will foster a highly effective teaching workforce in the United States.