It's a basic economic principle: You can get a better deal when you buy in bulk. That's why consumers form buying clubs -- to pool their buying power and get better deals from merchants. 

Fifty of America's largest employers just announced they're joining together in a buying club to bargain directly with drug makers in order to get low drug prices on behalf of their five million employees and families. It's a smart move. Their drug bills rose over 9 percent last year, following 8 years of double-digit increases. 50 big employers representing 5 million people have a lot of bargaining clout. They can stem the rising tide. 

And this is just the start. With these kind of savings, it's only a matter of time before every employer in America joins a buying club to negotiate low drug prices. 

Of course, when it comes to big purchasers with a lot of clout, the United States government is the 3,000 pound guerilla. For years now the Department of Veterans Affairs has been using its buying power to negotiate low drug prices for veterans. 

So maybe you'd think that Medicare -- representing all the nation's seniors -- would use its mammoth buying power to get even bigger drug discounts for them. But you'd be wrong. The new Medicare drug bill prohibits Medicare from negotiating deals with drug companies. The pharmaceutical industry used its clout with the Republicans in Congress who designed the bill to prevent such bargaining. 

Starting this month, seniors can get cheaper drugs by using Medicare discount cards. But because Medicare can't do what the Veterans Administration does -- can't do even what private employers are now joining together to do -- the Medicare discounts are limited. 

The consumer group Families USA has found that Medicare discount card prices on the most frequently prescribed drugs for seniors are at least 50 percent higher than the drug prices available to veterans. And you can bet that as America's major employers pool their bargaining power, they're going to get even better deals for their employees. 

This is crazy. Here we have private-sector employers using their clout to get drug discounts, while Medicare is barred from doing the same thing. Congressional Republicans, who champion the free market and tell us repeatedly that the private sector is more efficient than the public, have prevented the public sector from being more efficient -- and saving money for older Americans. Go figure.