Wage and price controls then in effect prevented employers from giving raises, but because the government regarded health insurance as a tax-free benefit, employers used it to fatten compensation packages for workers.
Employers are used to not providing raises for workers. 
mnli hypothesis: Employers are used to not providing raises for workers.  premise: Wage and price controls then in effect prevented employers from giving raises, but because the government regarded health insurance as a tax-free benefit, employers used it to fatten compensation packages for workers.