There is no data from the future

The Devil’s Advocate™ →Go uptown Something simple but utterly unpredictable, yesterday. It is quite entrancing, isn’t it? Even though it is just a gif. In which the curmudgeonly old sod puts the world to rights. Index — Click ᐅ to expand: The Devil’s Advocate Tell me more Sign up for our newsletter — or just get in touch: for ½ a weekly 🍺 you get to consult JC. Ask about it here.

Something that should be so utterly obvious it need not be said, but which nevertheless forms the backbone of the most common disclaimer on the planet. That we know only what we know, and cannot know what comes next, is a lesson that should have been beaten into us — with fables such as the inductive turkey who gets quite the surprise come Christmas, the jointed pendulum, the disastrous history of the financial markets — but which has been underestimated by reductionist types who labour under the illusion — delusion, really — that future states of the world can somehow be extrapolated for past ones.

See also

• Past results are no guarantee of future performance
• The Quickening
• Backtesting
• Profound ontological uncertainty