All neo-empirical accounting research has the underlying assumption of the efficiency of
markets – the efficient markets hypothesis (EMH). It is referred to as an “hypothesis” because despite
more than forty years of research designed to test the hypothesis all attempts to date have failed to
confirm it. Therefore, consistent with the generally accepted process of theory construction which
states (simply) that a theory is a confirmed hypothesis, it remains an hypothesis. The EMH emerged in
the 1960s from the work of researchers at the University of Chicago trained in economics and finance
and working in the areas known as portfolio theory and employing the capital assets pricing model
(CAPM). It was then taken up by accountants also working and studying at the University of Chicago
and, as stated, it has been the cornerstone of a considerable amount of research over the last forty years.
The EMH is an assumption about the relationship of information to security prices. The research area is
usually referred to as capital markets research but the EMH has had implications for other research
areas as well. Two Australians working at the University of Chicago, Ray Ball and Phillip Brown, are
regarded as the first to engage in capital markets research in accounting and their work (Ball and
Brown, 1968) has had a vast number of citations. Another seminal work was that by Bill Beaver
(1968).