There are at least 8 different approaches, for example to forecasting population number.
- Suck it and see: don’t anticipate outcomes; live in the moment.
- Predict using normative model: assumes causation by binary events, e.g heads or tails with 10 coins give a bell-shaped range of outcomes with a mid-range value e.g. 5 heads being most probable.
- Predict using Poisson distribution: assumes complex chain of natural events, e.g Per annum deaths by horse-kick in the Russian cavalry. Outcomes are snapper fish shaped: a blunt nil nose, a fatly probable mid-section and a long tailing off of multiple events.
- Predict using rectangular distribution: roulette-like equiprobability; caused by random luck.
- Deterministic model: calculates what outcome and when.
- Prescriptive forecast: plumps for an outcome to reduce speculation and acts as a self-fulfilling prophecy. Beware of governments bearing false forecasts.
- Intervention: someone controls occurrence of an outcome.
- Faith: relies on divine intervention.
We are usually ready to believe in someone spruiking a good future.
My novel The Grass is Always Browner is political fiction thriller. It tells a story about Australia 250 years in the future.