“…Once the situation becomes even somewhat realistic, controversies immediately emerge. See, for example, Fernández (2004Fernández ( , 2005Fernández ( , 2006, Nyborg (2006, 2007), Ruback (2002), Booth (2002Booth ( , 2007, Sabal (2005Sabal ( , 2007, Qi (2010), Pereiro (2002), Johnson and Qi (2008), and Graham (2000), among many, regarding how to value tax shields under a variety of circumstances.…”