here's what I've been told second hand...so take with grain of salt...
Apparently large production firms will enter into large contracts with firms that handle things like CG effects, contracting sets, SAG, etc on a certain amount of work. For instance, they may enter into a contract with a contruction firm for x number of dollars in sets and construction or with an airfield for x number of flights for a season. After all their large hyped up movies get made up, they go through the B pile of screenplays and look for films that will allow them the most use of whatever is left on contracts after the "blockbusters" have run their course. So if they haven't used up a lot of flights on their contract to an airline, they may pick up a movie that features lots of foreign locations to buffer out the contract and HOPE they recoup their money or come out with something like "just married" that makes them money. It's a factor of investment. If they allow their contracts to expire, they get back a fraction or nothing of what they agreed to, but another film may bring back more money.
I used to take it as urban myth, but then I see things like "Dude, where's my car" get made...and it starts to make more and more sense.