Goodwill represents the difference between the market value of a purchased firm and
the sum of fair values of recognized net assets. The initial valuation of goodwill is
relatively straightforward, but the valuation of goodwill subsequent to the acquisition
is inherently subjective, since goodwill is not a separable economic asset. Goodwill can
only be realized by the sale of the entire firm (or a unit of the firm if the goodwill is
specific to a unit).