“…Marsh 2003use a method for measuring total shifts in demand that vary independently between years in the form of an index approach, and apply the index to measure demand shifts in the US retail beef market. The approach was popularized by Purcell (1998), and has in recent years been applied to create demand indices for salmon and lamb (Asche, Dahl, Gordon, Trollvik, & Aandahl, 2011;Braekkan & Thyholdt, 2014;Shiflett, Purcell, & Marsh, 2007) as well as several product forms of beef and pork in the US (Tonsor & Schroeder, 2017). We extend the approach by decomposing the total demand shift into predicted and unexplained impacts on demand, in line with the distinction made by Taylor &Taylor (1993) and Karagiannis & Velentzas (2004).…”