It is unfair to reward extra achievements on top of the base level. To provide societal value from education, the base level of performance in education is already set very high. This means that even teachers who perform at base level are already working very hard to provide the societal value we require. Any difference above that already very high level is likely the result of luck and talent, both on the part of students and teachers themselves. Rewarding fortunate individuals for something they themselves didn't create is unjust and can only make other jealous.  Moreover, many students may enter the school system- at various stages- accompanied by a range of external advantages and disadvantages. A student’s home environment is a major influence on their ability to achieve when in the school environment. Although a teacher’s pastoral role is growing, there is little that they can do to address poor parenting, or to encourage the engaged, stimulating parenting that produces some of the most able pupils.