Passage Summary: Local companies want more government protection from foreign rivals, but they've already had ten years of it, and the economist says that's plenty of time if protection was actually going to work.

Reasoning: Machinery firms claim they need more time under protection to become competitive, but they have already had ten years, which the economist asserts is a sufficient duration for such a goal to be achieved.

Analysis: The economist sets up a conditional framework: if protection were effective, ten years would be enough time to see results. Since the firms are still claiming they aren't big enough to compete after those ten years, the logical inference is that the protection has failed to achieve its purpose. Look for an answer choice that suggests further protection is unlikely to result in the success the firms are promising, as the 'sufficient' time has already passed.