Half of staffing buyers still use assignment limits--why?

When we surveyed staffing buyers in 2006 regarding contingent worker assignment limits, 51% said they had some kind of limit on length of assignment for such workers.  Limits varied widely from less than a year to more than a year.  The most recent buyer survey, completed a few months ago, found almost exactly the same result.  That's not what we expected.

In the past, buyers relied on assignment limits as a legal protection against co-employment confusion.  However, more recent legal advice--now fairly widely known--would argue that assignment limits do not offer the legal shield they were once perceived to grant.  One might therefore have expected a liberalization in assignment limits, but that has not occurred.  I can think of two possible explanations.

The first is that some staffing buyers may still be clinging to the old idea--that all they have to do is limit assignments and, with respect to co-employment issues, they're OK.  The second is that buyers see some institutional advantage in assignment limits, perhaps as a periodic check on contingent expense.

Either way, the argument for contingent assignment limits seems weak.  If buyers still think such limits resolve the co-employment conundrum, they are dangerously misinformed and may be bearing considerable risk.  On the other hand, if they are using assignment limits to control excess contingent usage, are they not also throwing the baby out with the bathwater?  Wholesale termination of any class of employee on a periodic basis--cost saving though it might be--surely also would include termination of many useful and productive employees.

I'd go on, but according to our procurement department's policy on maximum length of blogs, I am not allowed to write more than