Prior to 1979, there were no formal announcements of business cycle turning points.
The NBER does not define a recession in terms of two consecutive quarters of decline in real GDP. Rather, a recession is a significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales. For more information, see the latest announcement from the NBER's Business Cycle Dating Committee, dated 9/20/10.
There can be little doubt that inequity created by normal healthy capitalist economies, is the primary the cause of this phenomenon. Health economist and biostatistician Andreas J. W. Goldschmidt searched for patterns and proposed that there is a phase shift and overlap of the so-called Kondratiev cycles of IT and health (shown in the figure). He argued that historical growth phases in combination with key technologies does not necessarily imply the existence of regular cycles in general. Goldschmidt is of the opinion that different fundamental innovations and their economic stimuli do not exclude each other, they mostly vary in length, and their benefit is not applicable to all participants in a "market." 
Committee members participating in the decision were: Robert Hall, Stanford University (chair); Martin Feldstein, Harvard University and NBER President Emeritus; Jeffrey Frankel, Harvard University; Robert Gordon, Northwestern University; James Poterba, MIT and NBER President; David Romer, University of California, Berkeley; and Victor Zarnowitz, the Conference Board. Christina Romer of the University of California, Berkeley, resigned from the committee on November 25, 2008, and did not participate in its deliberations of November 28.