Here's the sequence of events which I think neither vladimir nor SteelLady will dispute (broadly):

1. 1990: some Serbs flee (mostly but not only - Dubrovnik is elsewhere - Slavonia and Krajina in) Croatia for Serbia before the war starts due to "harassment" or "rumours"
   
2. 1990: some other Serbs take up arms ("Log Revolution" in Krajina) also due to "harassment" and "rumours"
   
3. 1991-2: war - Republic of Serbian Krajina is established in Slavonia and Krajina and Croats in those areas flee to central Croatia.
   
4. 1993-4: ceasefire
   
5. 1995: Croatia retakes the Republic of Serbian Krajina and Serbs flee.

Now we go to the interpretations which can (and will) be disputed:

Though the actors must either be inconsistent or different actors - with different motives - to at the same time promote rumors designed to make the existing population flee and try to colonize. That is, when the existing population already is the desired one.

No, the existing population is very mixed. So if you're going to turn the area into a war zone you first have your people flee to the rearguard so you can take a clean shot at the others. And then you move back in. And then you're driven back out and the others move back in.

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith