How long do conditions need to hold at above average levels before the improvement is considered to be sustainable? We don’t know the answer to this. In part, this is because animal spirits are by no means mechanistic or predictable.
What matters for your investment plans is not just what you think about the future, but what you think your competitors think about the future. In part, this is because if your competitors are less than enthused about investing, the pressure for you to invest to avoid being left behind is lessened, and vice versa. Elevated risk aversion?