“…D-optimal designs have been obtained in the literature either under the utility-neutral setup or using the locally D-optimal/Bayesian approach. D-optimal designs have been obtained theoretically under the utility-neutral setup, for example, see Graßhoff et al (2003), Graßhoff et al (2004), Street and Burgess (2007), Street and Burgess (2012), Demirkale, Donovan, and Street (2013), Bush (2014), Großmann and Schwabe (2015) and Singh, Chai, and Das (2015). In contrast, in the locally-optimal and the Bayesian approach, D-optimal designs have been obtained using computer algorithms (see, Huber and Zwerina (1996), Sándor and Wedel (2001), Sándor and Wedel (2002), Sándor and Wedel (2005), Kessels, Goos, and Vandebroek (2006), , , Kessels et al (2009), Yu, Goos, and Vandebroek (2009)).…”