Wow, guys, I'm having poor egg counts, too, but I think I can tell who isn't laying eggs, because I have 4 hens, each one a different breed, and two RIRs, 1 year old - one lays dark large eggs and the other a much lighter color.
Then I have 4 pullets about 16 weeks old, all RIRs, one of whom is laying a cute little egg daily. From what I can tell, another one is getting ready to start laying because last week I had two "shell-less" eggs dropped in the back yard as though they had just slipped out unexpectedly, which is how the 1st RIR pullet started laying.
I got 4 layers from a gal who was rotating them out of her flock and rotating in new pullets. 3 of these haven't produced in the last week, which is when I began keeping records in earnest. I hate to say this, but I'm beginning to wonder if they are really 1 year old, as I was told, because their production has dropped dramatically since I got them (although the Red Leghorn is reliable). They were my only layers at first, so I know their egg shapes and colors and I know they were doing better.
I added two "yearling" RIRs to the mix about a month ago and these gals are popping out beefy eggs nigh on every day. There is some competition for nest space, though, because although I have four nest boxes, two are favored and one is favored more than the other. (I got an education about chicken sounds the first time Bossie and Baby had a nest standoff - growling, hissing, screaming!)
So - the reasons I've read for not laying are:
broodiness - n/a with mine
diet change - I just started them back on sunflower seeds, as they were used to those when they got here but I let 'em go for a while
emotional stress - they all seem very happy - no picking, lots of happy chatter - except for the nest competition. I DID have to move one of the nest boxes higher because the dogs would go into the coop and climb into it, but they never took an egg that I saw. But that was weeks ago. Oh, and I WAS in the hospital unexpectedly for 5 days and too sick to give instructions for good care to my daughter. That was 3 weeks ago.
moulting - n/a
old age - no way to be sure - I tried to check the teeth, but no luck
hiding eggs - there's just nowhere to do that here