In the excellent article “Beware the long tail” (SN: 11/5/11, p. 22), the areas under each curve in the figure “Spotting the tail” should be unity (the total probability must be one). Therefore, the red curve should be lower in the center than the black one.
Filson Glanz, Durham, N.H.
Yes, the area under each curve should add up to one. In this case the graphic was shown without a y-axis to illustrate the basic point about the shapes of such curves; it would have been more appropriate to have shown the curves separately rather than superimposed. —Rachel Ehrenberg
The graphic “Event prediction” shows the Shanghai Stock Exchange Composite Index starting to decline at the beginning of the predicted period (gray bar) in 2009, but the text states that the b