"The fact of being reported multiplies the apparent extent of any deplorable development by five to tenfold. Disaster is rarely as pervasive as it seems from recorded accounts. The fact of being on the record makes it appear continuous and ubiquitous whereas it is more likely to have been sporadic both in time and place. Besides, persistence of the normal is usually greater than the effect of the disturbance, as we know from our own times."
What is now called Tuchman's Law was first coined by American historian Barbara Tuchman in 1978 in her book A Distant Mirror: The Calamitous 14th Century. It states that the reporting of an incident or a practice leads to the fraudulent belief that that sort of incident or practice is considerably more commonplace than it actually is in fact. Since what is commonplace rarely gets reported, people will tend to believe that it is not common while the unusual, which gets reported frequently, is the more normal state of affairs. Tuchman observed that this is not only true today, where information passes more readily through a wider variety of media to a larger and more varied group of people, but it was true in the distant past as well.
Then again, Tuchman always was an optimist.