Addendum to Eleftheriou and Michelacakis (2016)

Following the publication of Eleftheriou and Michelacakis (2016a), it was brought to our attention that the problem identified and corrected in Eleftheriou and Michelacakis (2016a) affects more papers than just the Beladi et al. (2008). Two such instances of published papers that we know of are the Beladi et al. (2010a) and Beladi et al. (2010b). The aim of this short addendum is to warn the reader against the validity of the results in these two papers and perhaps others using the same basic duopoly model as in Beladi et al. (2008). We look into the origins of the fallacy and make an announcement of corrected versions of some of the affected conclusions referring elsewhere for precise details.