[Purview - subject cannot be edited... add spellcheck!]
Employers being responsible for providing health insurance dates back to WW2. At that time, insurance was relatively inexpensive and quickly became a common benefit/perk. With annual average increases in the double digits, the health care costs are crippling and bankrupting many of our companies.
The premium quoted by insurance companies licensed in your state is determined by several factors, the two that have the greatest impact are:
1) The mandated requirements by your state (mental health care, birth control, pregnancy coverage etc).
2) The demographics of your 'group' (the employees in your company)
If you work for a small company (and approximately 50% of Americans do), you are at a decided disadvantage to an identical individual working for Microsoft, IBM or any Fortune 500 company. The larger the number of employees, the more people to spread the cost of catastrophic care. Insurance companies use fairly complex mathematical formulas developed over years to determine the likely costs they will incur over the plan period based upon the demographics of the people in the group. The more people, the lower the average risk, and the lower the average policy cost.
This is why the large companies can provide better plans for less cost to their employees. As insurance costs continue to escalate, the small companies are limited in the plans and coverage they can afford to provide and the amount they can afford to pay. This often puts the employer and employee on different sides of the 'table' when it comes to health care selection.