The continuing Wal-Marticization of the West

Robert Robb at The Arizona Republic has a great take on Wal-Mart, health insurance and the working poor in yesterday's edition. He does a great service by getting to the heart of criticism about employer-provided coverage:

There's a planted premise at work here, however, that deserves to be surfaced and examined: that health insurance should be an employer obligation, and that employers who don't provide it are shirking their responsibility.

But why should health insurance be an employer obligation?