However, efforts to improve the quality of public school teachers face some difficult hur-dles, the most daunting of which is the growing shortage of teachers. Hussar (1998) estimatedthe demand for newly hired teachers between 1998 and 2008 at 2.4 milliona staggering fig-ure, given that there were only about 2.8 million teachers in the U.S. during the 1999-2000school year.'Underlying this prediction is the fact that the fraction of teachers nearingretirement age has been growing steadily over the past two decades and continues to do so.In 1978, 25.7% of elementary and secondary public school teachers were over the age of 45;by 1998 that figure was 47.8%.