domino effect

a domino effect (the effect which a situation or event has on a series of other situations or events )

Example 1: Young people can't afford even the small houses, so the people in those houses can't move on to the bigger houses. It's the domino effect. (CID)

Example 2: "It's sometimes necessary to remove a large tree from a forest so the small trees have room to grow. Without Marlowe, all these library bookshelves would have room for the works of other writers. There'd be room in the Elizabethan theater for other playwrights, people like Shakespeare, who wrote some decent plays." "I agree, " Heinlein put in. "There's also the fact that many of the people on the list had children. Removing one of them could cause a domino effect. We don't have that problem with Marlowe because he was gay." "A good point, but children aren't the only dominos," MacArthur added. "There's a children's game in which one builds a tower of blocks and then tries to take blocks out of the tower's foundation without causing it to collapse. That's what we're doing here, but the tower is Western civilization, and the next three names on that list are essential to keeping it standing ('Finalizing History', Analog Science Fiction & Fact, 2008)

see also
[ripple effect]

Dominoes are a set of small, rectangle-shaped pieces of wood or plastic, marked with spots on one side. If dominoes are placed standing next to each other, each one will knock the next one over.