Latino millennials, and the younger generation right behind them, are the largest part of a big demographic trend in the United States: they, and other young people of color together make up the majority of U.S. public school students now.

But as that trend continues to grow, the level of diversity in the teaching staff hasn't budged much at all. The ratio of teachers from backgrounds shared with their students continues to drop drastically, as the demographic shift in the young population far outpaces any changes in the public school system's hiring of teachers from underrepresented backgrounds.

A former high school English teacher in the New York City public school system, Travis J. Bristol spent time teaching educators at the Boston Teacher Residency Program before becoming a research fellow at Stanford's Center for Opportunity Policy in Education, where he studies trends in student learning. Bristol recently sounded the alarm on teacher diversity, demonstrating just how big the representation gap in public schools is these days.

"There is a troubling trend in education that is not getting enough attention: the growth of Latino teachers has not kept pace with the rising Latino student population -- and the number of black teachers is shrinking," wrote Bristol in Sunday's Washington Post.

Teacher Diversity Dropping

Bristol points out that the number of Black teachers over the decade from 2002 to 2012 dropped by huge percentages in major urban areas, especially relative to White teachers in the same school systems.

In New York City's public schools, for example, Black teachers left their jobs at a rate of 15 percent through those ten years, while 62 percent did the same in New Orleans. In contrast, only 1.9 percent of White teachers left New York City schools in the same period of time, and New Orleans' school systems actually had a 3.3 percent increase in White teachers between 2002 and 2012.

For Latinos, there hasn't been a drop in the rate of Hispanic teachers. But the overall ratio between Latino teachers and their Latino students in U.S. public schools has declined, as a boom in Latino students has overtaken any gains in the proportion of teachers with Hispanic backgrounds.

For example, there are 7.8 percent Latino teachers in the national public education system, according to data from the National Center for Education Statistics. That's up from around 2002, when about 6.2 percent of teachers were from a Hispanic background.

But Bristol points out that currently, the proportion of Latino students has grown to 25.8 percent, creating a vast representation gap in education for Latinos, nevertheless.

Does it matter?

Yes, said Bristol, writing that this trend in education is a problem, along with what can be done to help. 

"Why should we care that the demographic makeup of America's teaching force does not mirror the racial/ethnic diversity of our students? Shouldn't the quality of the teacher matter more than the teacher's race in improving learning outcomes?" asked Bristol.

He answered those questions by noting that the two are not mutually exclusive, and pointed to research from several institutions that provide evidence that teachers of color, relative to White colleagues, have higher burdens of expectation for improving learning for students of color. But at the same time, they are more likely to meet them.

Studies Support "Added Value"

"There is, of course, a great danger in suggesting that simply providing Latino and Black teachers for Latino and Black students will close persistent learning and opportunity gaps," he concedes.

But nevertheless, Bristol says, data about the positive outcomes and, what he calls, the "added value" of diversity in teaching staff that reflects the backgrounds of their students should be enough to spur a new focus on raising the diversity levels of public school teaching staffs.

Bristol's policy recommendations do not call for quotas or draconian hiring measures to increase the number of teacher of color. Instead, he recommends more research on how to encourage and better support the retention of teachers from underrepresented backgrounds, along with boosting alternative pipelines for developing educators, such as Teach for America and Pathways2Teaching.

"As a nation, we are faced with the challenges of a teacher workforce that does not represent our country's increasing racial/ethnic diversity," said Bristol. In increasing teacher diversity through tweaks to current system, Bristol says the school system can boost the process of public education that honors the American ideal of "out of many, one."

Check out Bristol's piece in the Washington Post for more details and links to the half-dozen studies he cites supporting his position.