The ADA has been criticized on the grounds that it decreases the employment rate for people with disabilities and raises the cost of doing business for employers, in large part due to the additional legal risks, which employers avoid by quietly avoiding hiring people with disabilities. Some researchers believe that the law has been ineffectual. Between 1991 (after the enactment of the ADA) and 1995, the employment rate of men with disabilities dropped by 7.8% regardless of age, educational level, or type of disability, with the most affected being young, less-educated and mentally disabled men. Despite the many criticisms, a causal link between the ADA and declining disabled employment over much of the 1990s has not been definitively identified.