What contemporary theories explain employee motivation and performance?

"9.6 Contemporary Views on Motivation 6. What four contemporary theories on employee motivation offer insights into improving employee performance? According to expectancy theory, the probability of an individual acting in a particular way depends on the strength of that individual’s belief that the act will have a particular outcome and on whether the individual values that outcome. Equity theory is based on individuals’ perceptions about how fairly they are treated compared with their coworkers. Goal-setting theory states that employees are highly motivated to perform when specific goals are established and feedback on progress is offered. Reinforcement theory states that behavior is a function of consequences; that is, people do things because they know other things will follow."