volatility of a time series. We derive the main properties of the model and apply it to all agricultural commodities in the … volatility process and, according to homoscedasticity tests, outperforms the ARCH(1) and GARCH(1,1) models, some of the most … popular approaches used in the literature to analyze price volatility. Keywords: Agricultural prices, volatility, GARCH models. …

volatility. We develop a unified empirical framework to analyze the media's effects on both returns and volatility using insights … concentrated in soybeans and maize. We find robust evidence that media coverage decreases volatility for these agricultural … commodities on average for the period we study. The effects on volatility balance each other, with decreasing price coverage …