How Much Information? 2009 Report on American Consumers (PDF)
Date of Publication: December 2009
Last Update: January 2010

Executive Summary
In 2008, Americans consumed information for about 1.3 trillion hours, an average of almost 12 hours per day. Consumption totaled 3.6 zettabytes and 10,845 trillion words, corresponding to 100,500 words and 34 gigabytes for an average person on an average day. A zettabyte is 10 to the 21st power bytes, a million million gigabytes. These estimates are from an analysis of more than 20 different sources of information, from very old (newspapers and books) to very new (portable computer games, satellite radio, and Internet video). Information at work is not included.

We defined "information" as flows of data delivered to people and we measured the bytes, words, and hours of consumer information. Video sources (moving pictures) dominate bytes of information, with 1.3 zettabytes from television and approximately 2 zettabytes of computer games. If hours or words are used as the measurement, information sources are more widely distributed, with substantial amounts from radio, Internet browsing, and others. All of our results are estimates.

Previous studies of information have reported much lower quantities. Two previous How Much Information? studies, by Peter Lyman and Hal Varian in 2000 and 2003, analyzed the quantity of original content created, rather than what was consumed. A more recent study measured consumption, but estimated that only .3 zettabytes were consumed worldwide in 2007.

Hours of information consumption grew at 2.6 percent per year from 1980 to 2008, due to a combination of population growth and increasing hours per capita, from 7.4 to 11.8. More surprising is that information consumption in bytes increased at only 5.4 percent per year. Yet the capacity to process data has been driven by Moore's Law, rising at least 30 percent per year. One reason for the slow growth in bytes is that color TV changed little over that period. High-definition TV is increasing the number of bytes in TV programs, but slowly.

The traditional media of radio and TV still dominate our consumption per day, with a total of 60 percent of the hours. In total, more than three-quarters of U.S. households' information time is spent with non-computer sources.

Despite this, computers have had major effects on some aspects of information consumption. In the past, information consumption was overwhelmingly passive, with telephone being the only interactive medium. Thanks to computers, a full third of words and more than half of bytes are now received interactively.Reading, which was in decline due to the growth of television, tripled from 1980 to 2008, because it is the overwhelmingly preferred way to receive words on the Internet.

See authors' blog for discussion and additional information about the report.