Who gets laid off first?

The last post ("Who gets hired first?") has attracted a great number of comments, many of which I intend to address in the coming days. Thanks to all for the great commentary. But the corollary question hasn't been asked here; that is, when it comes time to lay people off, who gets the ax first?

Layoffs are particularly painful for a company. In my short industrial experience, I saw 2 of them and there was a third within a year. The following chart represents what I've seen in layoffs:

While layoffs often appear random to the bench-level chemist, it does seem that they affect the more experienced a lot more than the less experienced. In addition, middle management appear to be affected more than most (thus the "1st" tag on moderately experienced PhDs.) Ugh. This stuff needs to be analyzed, but is so unpleasant.

I'd love to get an insider's perspective on this. Also, I don't think the above chart is entirely correct. Maybe I need a poll. Readers, is the chart accurate? What are your thoughts as to how this happens?