One of the first factors that people think about when they think about motivating employees is compensation. While people do not only work for money, the money they get is clearly important. It is important both for its own sake and as an indicator of how much the employer values them. As an example of this, follow the link below. It describes how some teachers feel that they are not valued because they have not had a raise in at least five years.
Not all factors that motivate employees have to do with money. Employees can be motivated if their bosses treat them fairly and demotivated if their bosses do not. I have read, for example, many accounts of professional athletes losing motivation because they felt their coach was criticizing them unfairly or excessively. Conversely, I have read many accounts of athletes who said they were motivated to work hard because they knew their coach would treat them fairly.
Finally, employees can be motivated if their bosses appear to care about the balance between their professional and personal lives. I know a woman who was very upset and demotivated when her work decided that she would only be allowed to take two weeks of leave after the birth of her second child. She had been allowed to take much more leave after her first child and was motivated by that policy. When the policy was changed, she felt that her employer cared little about her personal and family life and the way her work impacted that aspect of her life.