Famous Forecasting Quotes


"Those who have knowledge, don't predict. Those who predict, don't have knowledge. "

--Lao Tzu, 6th Century BC Chinese Poet

Wise words from a long time ago.

"I have seen the future and it is very much like the present, only longer."

--Kehlog Albran, The Profit

This nugget of pseudo-philosophy is actually a concise description of statistical forecasting. We search for statistical properties of a time series that are constant in time--levels, trends, seasonal patterns, correlations and autocorrelations, etc. We then predict that those properties will continue to look the same in the future as they do today.

"Prediction is very difficult, especially if it's about the future."

--Nils Bohr, Nobel laureate in Physics

This quote serves as a warning of the importance of testing a forecasting model out-of-sample. It's often easy to find a model that fits the past data well--perhaps too well!--but quite another matter to find a model that correctly identifies those features of the past data which will be replicated in the future.

"The best qualification of a prophet is to have a good memory. "

--Marquis of Halifax,

This quote is very applicable to statistical models which require long periods of past data in order to be reliably estimated.

"Some things are so unexpected that no one is prepared for them. "

--Leo Rosten in Rome Wasn't Burned in a Day

This is particularly relevent to non-stationary processes such as the the climate and the business world. For example, the appearance of the Antarctic ozone hole in the mid 1970s was quite a surprise.

"An unsophisticated forecaster uses statistics as a drunken man uses lamp-posts - for support rather than for illumination. "

--After Andrew Lang

Careful application of statistics is essential for obtaining and judging predictions and can provide much insight into the assesment of skill in the predictions.

"An economist is an expert who will know tomorrow why the things he predicted yesterday didn't happen today. "

--Evan Esar

Post-analysis of predictions is often very revealing especially concerning model weaknesses.

"If you can look into the seeds of time, and say which grain will grow and which will not, speak then unto me. "

--William Shakespeare

The Bard's elegant demand for a good prediction.

"A good forecaster is not smarter than everyone else, he merely has his ignorance better organised. "


Prediction involves maximising the ratio of signal to noise, with the signal being the predictable component and the noise been unpredictable events.

"My interest is in the future because I am going to spend the rest of my life there. "

--C.F. Kettering

This is not completely true since C.F.Kettering spent most of his life in the present !

"To expect the unexpected shows a thoroughly modern intellect. "

--Oscar Wilde

A classic one-liner from the master of wit.

"This is the first age that's ever paid much attention to the future, which is a little ironic since we may not have one. "

--Arthur C. Clarke

A touch pessimistic perhaps ?

"I always avoid prophesying beforehand because it is much better to prophesy after the event has already taken place. "

--Winston Churchill

A shrewd remark about hindcasting from a shrewd politician.

"Prophesy is a good line of business, but it is full of risks. "

--Mark Twain in Following the Equator

A truism that many have experienced personally.

"Forecasting is the art of saying what will happen, and then explaining why it didn't! "

--Anonymous (communicated by Balaji Rajagopalan)

The converse is also true: saying what WON'T happen, and then explaining why it DID happen ! See the large El Nino of 1997 for a recent example.

"Cutting up fowl to predict the future is, if done honestly and with as little interpretation as possible, a kind of randomization. But chicken guts are hard to read and invite flights of fancy or corruption. "

--Ian Hacking in The Emergence of Probability

Maybe chickens aren't the easiest of models to use for prediction.

"Wall Street indices predicted nine out of the last five recessions ! "

--Paul A. Samuelson in Newsweek, Science and Stocks, 19 Sep. 1966.

False alarms are an embarassing subject for those involved in prediction.

"He who lives by the crystal ball soon learns to eat ground glass."

--Edgar R. Fiedler in The Three Rs of Economic Forecasting-Irrational, Irrelevant and Irreverent , June 1977.

A cautionary career note based on past experience.

"The herd instinct among forecasters makes sheep look like independent thinkers. "

--Edgar R. Fiedler in The Three Rs of Economic Forecasting-Irrational, Irrelevant and Irreverent , June 1977.

Maybe we should let sheep have a go at forecasting ?

"If you have to forecast, forecast often. "

--Edgar R. Fiedler in The Three Rs of Economic Forecasting-Irrational, Irrelevant and Irreverent , June 1977.

A useful survival tactic.

"It is far better to foresee even without certainty than not to foresee at all. "

--Henri Poincare in The Foundations of Science, page 129.

A pragmatic remark from one of the foundation builders of chaos theory.

"It is said that the present is pregnant with the future. "

--Voltaire in The Portable Voltaire.

This remark about child birth is particularly relevent to the problem of predicting El Nino climatic events.

"Forecasting future events is often like searching for a black cat in an unlit room, that may not even be there. "

--Steve Davidson in The Crystal Ball.

Future events, like cats, can prove to be elusive !

"Foreknowledge of the future makes it possible to manipulate both enemies and supporters. "

--Raymond Aron in The Opium of the Intellectuals.

... and also funding agencies !

"The future isn't what it used to be !"

-- anonymous (supplied by Joseph Silling)

Believed to be a comment made by an IBM executive concerning predicted future trends in personal computing around 1992.

"I foresee that man will resign himself each day to new abominations, and soon that only bandits and soldiers will be left. "

--Jorge Luis Borges in The Garden of Forking Paths.

A rather pessimistic prediction for the future.

" It is often said there are two types of forecasts ... lucky or wrong!!!! "

-- in "Control" magazine published by Institute of Operations Management

An interesting binary approach for classifying all forecasts.

" The lily shall remain in a merry world; and he shall be moved against the seed of the lion, and shall stand on one side of the country with a number of ships. Then shall the Son of Man, having a fierce beast in his arms, whose Kingdom is the land of the moon, which is dreaded throughout the world. With a number shall he pass many waters, and shall come to the land of the lion, looking for help from the beast of his country, and an eagle shall come out of the east, spread with the beams of the Son of Man, and shall destroy castles of the Thames. And there shall be battles among many kingdoms. That year shall be the bloody field, and lily F.K. shall lose his crown, and therewith shall be crowned the Son of Man K.W., and the fourth year shall be preferred. And there shall be a universal peace over the whole world, and there shall be plenty of fruits; and then he shall go to the land of the Cross. "

-- Mother Shipton a famous 15th century prophet

In the days before computers, this is how predictions were often made.

" I never think of the future, it comes soon enough. "

-- Albert Einstein

The final word on the subject ?

If you have any other quotations relevant to forecasting, then I would love to see them. Please drop me a line HERE !!

Copyright 1997,1998  
D. B. Stephenson  
Permission is granted to make copies for individual use, but not for redistribution.
Last Updated: 28 December 1998.
Comment Comment on this page.

If you would like to comment on this particular web page or on our website in general, we would be pleased to receive your views via the box below:

Your Name :
Your Email Address :
Comments/Feedback :

valid xhtml valid_css2 valid_firefoxie