If you thought teacher layoffs were bad last year, run for cover. A wave of teacher layoffs will likely sweep the nation this coming spring. The number of layoffs is sure to surpass 2009's figures--60,000 teachers let go--and this year there is no stimulus package to help bail out districts.

Education Secretary Arne Duncan told a recent meeting of the National Governors Association on Sunday that he is "very, very concerned about layoffs."

In a new NCTQ paper, we explore the factors determining teacher layoffs, which are not surprisingly based on seniority in about 75 percent of the 100 districts in our Tr3 database. There are a number of notable instances in which districts use a combination of factors, including teacher performance, to decide who must go. Learn more about what a number of districts are doing as alternatives to the seniority system here .