Text 1 From West Virginia to Arizona,public-school teachers are in revolt.They are demanding better pay,and they deserve it-so long as their salaries are tied to their performance.It"s not that U.S.teachers are underpaid;the median income for the country"s l million high-school teachers,for example,is more than 50 percent higher than that of the general population.But relative to peers with similar levels of education,teachers are falling behind.In 1994,public-school teachers made only 2 percent less than college graduates in other fields;by 2015,the gap was 17 percent.Cuts in state education budgets have made the problem WOfse.In more than half of the country,aftcr adjusting for inflation,average teacher salaries have declined since the start of the century.In West Virginia,where pay has dropped by 8.9 percent since 2000,teachers went on strike in late February,forcing Iawmakers to pass a 5 percent pay increase for the next school year,Teachers"unions in Arizona,Oklahoma and Kentucky plan similar walkouts if their demands aren"t met.To avoid such an outcome-which hurts students the most-both sides need to compromise.Teachers shouldn"t have to work second and third jobs to make ends meet,as many say they do,even in states with low are fiercely defended by teachers"uuions.But they reduce the funds available for other priorities-like encouraging teachers to relocate to rural and low-income districts and addressing shortages of teachers in STEM subjects.Across-the-board pay increases for teachers may go some way toward improving student performance,but not far enough.Despite opposition from unions,school districts in at least 30 states have introduced performance-based bonuses for teachers.In schools where teacher pay is tied to student performance,test scores have nsen by the equivalent of three additional weeks oflearning.Districts with merit pay are better able to hire strong entry-level candidates and prevent high-performing teachers from leaving.Intemational comparisons bear out a basic,if self-evident,truth:how well students perform depends on how well they"re taught.The U.S.should pay its teachers more-and give the best ones incentives to show how much they"re worth.22.The word"walkouts"（Para.3）most probably means