Sticky wages?

I'm not sure I understand how economists (including Mark Thoma) can look at this data:

... and say:

Taken at face value, this analysis suggests the presence of some amount of wage rigidity.

24% of people are reporting nominal hourly wage declines. Only 20% are reporting the same wage. That means something like 80% of people are reporting wage changes. They should check out the section of my paper on entropic forces and nominal rigidity. Or this post on macro rigidity and micro flexibility.