I do not have a specific, model-based prediction, but I will go on record here as saying that I expect Cuba’s current regime to fall within 4-5 years. My hunch is based on Cuba’s easing of travel restrictions. The BBC’s Sarah Rainsford thinks this is an important change too:
It was more than a year ago that the President Raul Castro said that the system would change and the Cubans have been waiting impatiently ever since. So, it is a big deal. It does mean a little bit more freedom for people here on the island who want to travel. It essentially means that they won’t face a bill of $350 all told for all the paperwork involved which, for a country where the average salary…average monthly salary is $20 is obviously very significant.
Reading a paper by Timur Kuran from 1989 on revolutions (ungated pdf), I came across this quote by Tocqueville that seems apropos:
[I]t is not always when things are going from bad to worse that revolutions break out. On the contrary, it oftener happens that when a people which has put up with an oppressive rule over a long period without protest suddenly finds the government relaxing its pressure, it takes up arms against it. Thus the social order overthrown by a revolution is almost always better than the one immediately preceding it, and experience teaches us that, generally speaking, the most perilous moment for a bad government is one when it seeks to mend its ways.
Kuran thinks that revolutions are inherently unpredictable, but I would argue that this mechanism proposed by Tocqueville can inform our expectations about what will happen in Cuba–and elsewhere–in the coming years.