Are there any relevant examples of salary increases failing to change employees' abilities

Sure, here are some examples:

1. In 2014, Gravity Payments, a credit card processing company in Seattle, raised its minimum wage to $70,000 a year. While this move initially boosted morale and productivity, it also led to some unexpected consequences. Some employees felt that the increase was unfair to those who had worked at the company for a longer period of time or had more demanding roles. This led to a decrease in overall job satisfaction and performance among some employees.

2. A study published in the Journal of Applied Psychology found that while pay raises can increase job satisfaction, they don't necessarily improve an employee's job performance. The study found that the relationship between pay and job performance is very weak. This suggests that while a salary increase can make an employee happier, it doesn't necessarily make them work harder or better.

3. In another example, the Los Angeles Unified School District implemented a salary increase for teachers in an effort to improve student performance. However, a study conducted by the National Bureau of Economic Research found that the salary increase did not lead to any significant improvement in student performance.

These examples show that while salary increases can improve job satisfaction and morale, they don't necessarily lead to improvements in job performance or ability. Other factors, such as job design, management style, and workplace culture, can also play a significant role in an employee's performance and ability.