As do a few of you, I, too, believe it is too soon to draw any major conclusions regarding the effect on the deer harvest just from going from a 3 to a 2-buck limit.
But I'll share with you a couple "trends" I believe were magnified a bit because of the 2-buck limit. Now just what effect these have on the composition of the deer harvest ongoing, yet to be seen.
1) Less bowhunting prior to the November muzzleloader season.
Ever heard "too much of a good thing"?
Many hunters had already been discovering that doing a little LESS bowhunting immediately prior to muzzleloader season contributed to greater hunting success once afield with a more effective weapon. So this trend didn't begin with the 2-buck limit, but I do believe the lower buck limit magnified and accelerated this trend. Among TN's hunters, I observed the least amount of archery deer hunting I've seen in over 30 years; but possibly the most November muzzleloader season hunting ever.
2) Increasing, but self-imposed and purely voluntary, criteria
regarding what constitutes a "shooter" buck by a growing number of hunters.
So how could THIS increase the buck harvest?
Perhaps in ways some haven't considered.
Many hunters doing this last year (yes, even when we had a 3-buck limit) helped to create more 2 1/2 & 3 1/2-yr-old bucks in this year's deer herd. Never mind that many of this year's 2 1/2's & 3 1/2's were "below average" antlered (as the larger antlered were mostly killed in the prior year), even a below average 2 1/2 can still be larger than a "large" antlered 1 1/2. And a below average 3 1/2 can still be a good bit larger than an average 2 1/2.
No doubt in my mind, the Tennessee deer herd had more 2 1/2 & 3 1/2-yr-old bucks within it at the beginning of the 2015 deer season than it had at the beginning of the 2014 deer season. There would likely be more bucks killed in 2015 than 2014, even if we had had a 1-buck limit in 2015. But also, if we had retained the 3-buck limit, our 2015 buck harvest would have been about 5% higher than wherever it ends up under a 2-buck limit. That 5% may not sound like much, just keep in mind it equates to more like 10% after 2 years, or 15% after 3 years.
Keep in mind there is still a bit of shift in "who" is taking these bucks. Hunter success (measured in the number of hunters taking at least 1 buck annually) appears to be increasing under a 2-buck limit. Might have anyway, but it had not over the past several years. Bottom line is that with fewer hunters killing 2 or 3, more hunters are killing at least 1.