1st International Congress on Environmental Modelling and Software - Lugano, Switzerland - June 2002
Keywords
ecological patents, trends, volatility, garch, star-garch
Start Date
1-7-2002 12:00 AM
Abstract
Ecological patents have been increasing steadily over time. The paper analyses trends and volatility inecological patents in the USA from 1975 to 1997. Germany contributed more than 10% of the total number of USecological patents, and is by far the strongest foreign performer. The time-varying nature of the volatility of thepatents ratio, namely the ratio of US ecological patents to total US patents, is examined using monthly data fromJanuary 1975 to December 1997. The regime-switching LSTAR-GARCH model is found to be optimal formodelling the ecological patents ratio.
STAR-GARCH Models of Ecological Patents in the USA
Ecological patents have been increasing steadily over time. The paper analyses trends and volatility inecological patents in the USA from 1975 to 1997. Germany contributed more than 10% of the total number of USecological patents, and is by far the strongest foreign performer. The time-varying nature of the volatility of thepatents ratio, namely the ratio of US ecological patents to total US patents, is examined using monthly data fromJanuary 1975 to December 1997. The regime-switching LSTAR-GARCH model is found to be optimal formodelling the ecological patents ratio.
