This article considers a GARCH process, generally named as GARCHX, in which the additional covariate is specified as a positive fractionally integrated process. Recent work on MEM, HEAVY, and Realized GARCH models falls in this category. We investigate the asymptotic properties of this process and show how it explains stylized facts of financial time series such as the long memory property…

To what extent and in what ways is metaphorical thought relevant to an understanding of culture and society? More specifically: can the cognitive linguistic view of metaphor simultaneously explain both universality and diversity in metaphorical thought? Cognitive linguists have done important work on universal aspects of metaphor, but they have paid much less attention to why metaphors vary bot…