Traffic at most newspaper Web sites has been flat or is falling, says a new Harvard study that is mentioned on Alan Mutter’s Reflections of a Newsosaur blog. The study looked at 160 newspapers and found that the growth in newspaper site readership was produced almost entirely by the NY Times, USA Today and Washington Post. Small- and mid-size paper Web sites are losing ground. At the bottom of Mutter’s blog entry is a NielsenNet ratings chart that shows SFGate readership fell 14.6 percent from April to July. Also, E&P notes that the Mercury News has fallen out of the Top 30 list of newspaper Web sites in July. Mutter (pictured) is a former Chron assistant managing editor in the 1980s who now is involved in venture capital for new media.