Predominantly liberal/social democrat, but unlike most left-wingers (here at least), I'm isolationist and anti-immigration

I think you're mischaracterizing the motivations of (most) progressives. I don't believe that they are motivated by a desire to punish the privileged.

Read what progressives like Ezra Klien actually write.

y'all a bunch of paranoid delusional mentally-disabled freaks who can't get laid

Based on the phrase "change which charities I donate to" I had assumed he or she was already donating to multiple charities, presumably including action in subsaharan africa.

The money being donated to charities that are not in Sub-Saharan Africa would be better donated to charities that are. Even if that were not the case, that would just mean that the money that is donated to charities that are in Sub-Saharan Africa would be better donated to charities that are not. The money from a single donor isn't enough to change which continent you should donate to.

Also can you explain the "magnitude" thing?

An order of magnitude is a power of ten.

I'm not sure I follow your definition of "effectiveness".

Here's an example of what I mean.

The Seeing Eye trains dogs to help mitigate the effects of blindness for about $50,000 each. The Fred Hollows Foundation performs cataract surgeries to cure blindness for about 25$ each. It's not generally clear how to relate how much good two different charities are, but it is pretty obvious that a cataract surgery does more good than a guide dog, and for 2,000 times less. Thus, the Fred Hollows Foundation is more than three orders of magnitude more cost-effective than The Seeing Eye. Even if The Seeing Eye was tax-free and the Fred Hollows Foundation was taxed at 99.9%, it would be worth while to donate to The Seeing Eye.

What's the assumption? You just told me that you're planning on donating to a Canadian charity, and that it's because Canada still has problems. I suppose I assumed that you're only donating to one country. If not, there are further problems with your donation habits.

Part of it is tax refunds.

The effectiveness of different charities varies by orders of magnitude. I don't think tax refunds will make a notable difference.

Part of it is that there are problems in our own country as well that need solving, not just in sub-Saharan Africa.

Relvant xkcd comic. There will always be problems in your country. If you haven't gotten to the point where you'll start helping sub-Saharan Africa yet, when will you?

It's really hard to measure lasting improvements, which does bias the choice of interventions Givewell considers, but they endorse direct transfers because it has been shown to be more effective at lasting improvements than other things they've considered.

Someone who says something like the first sentence generally means something like "questions that are significant and in an area I am concerned with"

If you don't have any open questions in that category, then you aren't really living as an intellectual.

In science questions are like a hydra. After solving a scientific problem you often have more questions than you had when you started.

Schwartz's article on the issue is quite illustrative. If you can't deal with the emotional effects that come with looking at an open question and having it open for months and years you can't do science.

You won't contribute anything to the scientific world of ideas if you can only manage to concerned with an open question for an hour and not for months and years. Of course there are plenty person in the real world who don't face questions with curiosity but who in pain when dealing with them. To me that seems like a dull life to live. because the question doesn't concern themselves with living an intellectual life.

Why do you want Canadian charities?

So that you can get a tax break or an employer match?
That makes your money about twice as effective, but changing charities often makes a much larger difference. So don't restrict to charities registered in Canada.

Givewell already analyzes the effectiveness of various charities, so I'd start there.