I just spent a bit of time reviewing the charity tax laws in Canada.
The Watchtower Society in Canada files tax as a charity and as such is governed by those laws. The GB may be the "guardians of doctrine" but when it comes to money, the CRA are the "guardians of $".
To ensure that a charity really does what a charity is supposed to do - collect money and spend that money on charitable activities - the CRA has what is called a "disbursement quota". The optimum disbursement quota is 20/80. In other words - 20 percent of incoming money can be spent on administration and expenses and 80% is to be directed towards charitable activities.
In Canada, the money spent on charitable activities can involve the transfer of donated money to a "qualified donee". The Canadian branch's qualified donee is the Watch Tower Bible and Tract in NY (or is it the Pennsylvania one? hard to keep track of all the corporate names).
If a charity wants to spend money on capital purchases or put money into buildings (Kingdom Halls) they have to receive written permission from the CRA.
I think that, in Canada at least, the charity tax laws, especially the disbursement quota, is what is driving the WT's demand for donations. And, the money being drained into expansion projects increases the amount they are required to put towards that 80% figure of charitable activities. Building projects don't necessarily qualify.
I hate tax law. It makes my brain hurt.
*to add - the question - "are you under any parent organization?"...or something like that...was answered "No". Huh. So the Canadian Branch apparently doesn't have a parent organization. They claim to be independent of the top WT corp. Not sure how that works. And all the directors claimed to be "arm's length" from all the other directors. Hmmmm.