What is the difficulty in measuring the brand equity of a brand like Coca-Cola?

Need to know info about discussion question:

I will start the discussion with a quote (from a coauthor's paper, which I recommend reading): "John Stewart, co-founder of Quaker Oats, put the value of the brand in perspective when he said, ‘If this business were split up, I would give you the land and bricks and mortar, and I would keep the brands and trademarks, and I would fare better than you.' In the same way, a McDonald's CEO opined that ‘a McDonald's board member who worked at Coca-Cola once talked to us about the value of our brand. He said if every asset we own, every building, and every piece of equipment were destroyed in a terrible natural disaster, we would be able to borrow all the money to replace it very quickly because of the value of our brand. And he's right. The brand is more valuable than the totality of all these assets" (Stanton and Herbst 2005, p. 9). And finally, "brands allow the company to charge more than the equivalent commodity or private-label alternative. In other words, a brand is empowering