ABSTRACT
Many economists and other social scientists adopt a very casual approach to the meaning and origins of probabilities. They almost always seem quite content to preserve a comfortable familiarity with some basic probabilistic concepts — such as distribution or density functions with convenient mathematical properties, reasonably stable parameters, simple stochastic processes with sufficient stationarity over time and a few referential statistics for both location and dispersion (e.g. mean, median or mode, and variance or standard error). Probabilities themselves are generally separated only into 'subjective' and 'objective' types without much consideration of what features these qualifiers should entail, other than some notion that one type might just involve individual or personal mental activity while the other type reflects an external or contextual property. Both types are presumed to obey a group of similar (perhaps identical) rules for consistency, completeness and coherence.
