Grade inflation may be caused by decreases in academic standards or increases in student performance or both. The pressure to reduce standards placed on teachers can come from parents, students, and schools. This is especially true since, if other schools or teachers are inflating grades, any school or teacher that takes a "hold out" stance will place its students at a disadvantage. Some educators may feel pressured to give higher grades for fear of students complaining and receiving bad course evaluations, thereby diminishing their reputation and causing them to face lower enrollment in their classes. Indeed, Professor Harvey Mansfield gives two grades to students at Harvard, an official inflated grade, and an unofficial grade that he feels a student deserves. Committees commonly use course evaluations obtained by teachers to help make decisions about awarding them promotion and tenure. A teacher may improve mediocre evaluations by improving their teaching, but what comes most quickly to mind for achieving better evaluations is to give higher grades for assignments and exams. A comprehensive study by Valen Johnson shows a statistical correlation between high grades and high course evaluations. In a separate analysis of grades at Penn State, the onset of grade inflation in the 1980s corresponds with the onset of mandatory course evaluations.
Professor Hans Oberdiek of Swarthmore College explained during an introductory course in philosophy in 2003 that grade inflation began in earnest during the draft for the Vietnam War. Students with high enough grades could be exempted from the draft; so giving a student a C could cause him to be sent to Vietnam. Needless to say, professors gave higher grades more readily so as not to have this dire outcome hanging over their heads. Before the war, "I used to give out Cs like candy," Professor Oberdiek explained.
While pressures to reduce standard do exist, at some colleges and universities part of grade inflation is the result of increases in student performance. Over the last few decades, the quality of incoming students at some schools as measured by SAT scores and high school class rank has increased. But for many institutions with rising grades SAT scores have been stagnant. Even at institutions where SAT scores have risen, the magnitude of the rise in GPA cannot be explained by increases in student SAT scores alone. Other factors are responsible for rising grades.
Many schools exhibit increases in grades that may not be related to a decrease in academic standards.
There are alternative theories regarding the increase in student grades over the years, such as:
More schools offer pass/fail options.
Students are more focused upon career-preparation today, which means they are more likely to take classes which match their talents.
Computers have made students more efficient and allowed them to produce better work.
Cooperative learning approaches allow feedback on assignments which improves student work.
Students are working harder than ever before.
Countering these claims are the following arguments:
Pass/fail options are only taken by a small number of students that isn't not large enough to account for observed rises in GPA.
Students still have to fulfill distribution requirements so they are still taking classes outside their main interest areas.
Grade inflation persisted throughout the 1990s, a time when personal computer use had already saturated higher education.
Cooperative learning approaches are not common enough to account for observed rises in GPA.
Surveys of high school students and college students show that they are working less and are less engaged in academics.
A related point is that intelligence (at least as measured by the IQ scale) appears to be rising over time - a phenomenon known as the Flynn effect. However, SAT scores of students nationwide have not been rising.