VI. Cautions and Caveats in Forecasting
A. Psychological Biases to Forecasting
To a varying degree, the effectiveness of all of the forecasting methods is often
undermined by excessive optimism on the forecaster’s part, especially in new
product or new venture settings.
Forecasters often fall prey to what Dan Lovallo and Daniel Kahneman call
the planning fallacy, a tendency to make decisions based on delusional
optimism rather than on a rational weighing of possible gains and losses and
the probabilities thereof.
B. Common Sources of Error in Forecasting
Forecasters are subject to anchoring bias, where forecasts are perhaps
inappropriately “anchored” in recent historical figures even, though market
conditions have markedly changed, for better or worse.
Capacity constraints are sometimes misinterpreted as forecasts.
Another source of error in forecasting is incentive pay. Bonus plans can cause
managers to artificially inflate or deflate forecasts, whether intentionally or
otherwise.
o“Sandbagging”—setting the forecast or target at an easily achievable figure in
order to earn bonuses when that figure is beaten—is common.
Unstated but implicit assumptions can overstate a well-intentioned forecast.
Assumptions of awareness and distribution coverage at levels less than 100
percent, depending on the nature of the planned marketing program for the product,
should be applied to a forecast, using the chain ratio method.
C. Keys to Good Forecasting
There are two important keys to improve credibility and accuracy of a set of
forecasts of sales and market potential.
oMake explicit the assumptions on which the forecast is based.
oUse multiple methods. If the results of two or more forecasting methods
converge on similar results, that will build your and others’ confidence in
what the forecasts say.
Contingency plans should be developed to cope with the reality that ultimately
unfolds.
VII. Why Data? Why Marketing Research?
Obtaining market knowledge requires data.