I have been speaking about this issue since the mid 90s. First off, boys go where their parents want them to go, so it's not a scout burnout issue. It is an adult burnout issue at the cub level. While adults do burnout at the troop level, it's not the problem of cubs because the patrol method program gives the boys some control of their program.
At the cub level, adults are expected to manage a program for at least five years. Experts say the average volunteer gives 20 months before starting burnout. Adults don't just drop out after 20 months, but their effort has lost it's enthusiasm and the program suffers. The real problem comes with the Webelos because just to start the typical Bear leader is mother and has been an active leader between two to three years. Webelos hits them hard because not only are they are burned out, they don't feel they have the skills or knowledge for running a more outdoors boy scout skills program. The thought of camping outdoors in the heat or cold with a den of 9 year old boys has no appeal at all.
So what typically happens is either the burned out mother sticks it out as a Webelos leader without any energy for the responsibility or someone else is pulled heels dragging into the position. I found in my research that about 40% of Webelos leaders fall under the burnout scenario. There programs are basically boring without much push toward a future in the boy scout troop.
On a national average (at least 10 years ago) only about 50% of Webelos cross over into troops to continue their scouting experience. What is interesting about that statistic is that the scouts would have bailed out a year earlier during Webelos I if it not for the Arrow of Light award. Parents want their sons to learn the lesson of sticking with something to the end, so they encourage their sons to finish cubs.
I found that both parents and sons of burned out cub leaders don't even really consider the Troop program because they believe it will be the same boring experience as the Webelos. It's hard to get good numbers, but I believe that less than 25% (15 to 20%) of cubs who started at the tiger level make it to the troop program. That is why the cub adult burn out issue is such a big deal. And that is why I scuff off worrying about gays and transexuals making a difference in membership numbers. The real membership problem starts with the adult leaders in Cubs. Loose the adults and you loose the boys. Visa versa, keep the adults and you keep the boys. Drive the program to keep the adults and they boy membership will grow leaps and bounds. I saw it over and over.
Does one year in one way or another make an attempt at fixing the problem, yes to some degree. I did find a lot of burned out Wolf leaders. So the 20 months rule really does take a toll. But the real toll is the activities of the Webelos program. Webelos really does require someone with some enthusiasm. Not so much an outdoors experience, but someone willing to plan fun meetings with activities that appeal to boys with a lot of energy. I talked to a couple of Webelos leaders who never took their den on a campout or spent much time doing boy scout skills, but they planned fun active den meetings that they boys looked forward to each week. As a result, they crossover looking forward to the troop program. One of those leaders told me that when the boys got restless, she handed the boys a basket ball and told them to have some fun. See, it's not so much about having a camping outdoor skills experience to join a troop, it's having a good experience that appeals to the age maturity.
The reason the Tigers, and now Lions, is so demanding on adults is because the maturity between first grade and second grade is dramatically different. First grade is where youth learn the discipline of sitting and listening. AND, it is where they learn to read. I learned as a SM that printing out the words for songs and cheers doesn't work with Tigers. So I had to figure out other ways to introduce new songs and cheers. But, to my point, a Tiger scout still has the toddler maturity. And the problem is that when all the are groups are together, the program has to appeal from the least mature scout to the most mature scout. That is a huge range of maturity. How big? Some Scoutmasters I worked with agreed that the Tiger program alone almost doubles the number adults require to manage the whole pack. Our pack experience was much the same.
If the BSA really wants to recruit families of toddlers, they need to start a separate program like the Girl Scouts Daisy program so the adults in the pack don't have to manage a program with such a broad range in maturity. And, it's easier on the pocket book for first time parents. A Blue Cub Scout shirt is twice the cost of a T-shirt. And, a scout is less likely to out grow the shirt in three years where many Bears are looking to replace the shirt they stared with as a tiger. That may sound small to some here, but we found that entry fees is a big consideration for many parent considering the BSA at the Tiger age.
I hope that helps folks understand better the problem of adult burnout.