The New York Times tells us in their article, “A Seismic Change in Predicting HowEarthquakes Will Shake Tall Buildings” by Thomas Fuller
“There are going to be large changes coming,” Norman Abrahamson, a seismologist at the University of California, Berkeley, told hundreds of engineers gathered for the conference. “We now know how far-off our ground motion models have been.”
You are encouraged to read the N Y Times article.
If the engineers are right, all the decisions that are being made to allow development to go forward are based on incorrect calculations. The old model opens the door for developers while risking lives.