He would have a little more incentive but the costs of a house sitting vacant are pretty straightforward and anyone would have an incentive to avoid those. This could come about unexpectedly due to a lay-off but could come about for other unexpected reasons as well. It doesn't really matter if he's laid off or not, these facts remain:

• You should have a reasonable cushion so that a temporary interruption in employment does not mean foreclosure and financial ruin
• If you have to move, you want to sell or rent your house as soon as possible. Other things equal, buying with an eye towards the re-sell market is wise.