explains stock returns associated with the announcement of issuer exchange
offers. The major independent variables are changes in leverage multiplied by
senior security claims outstanding and changes in debt tax shields. Parameter
estimates are statistically significant and consistent in sign and relative magnitude
with model predictions. Overall, 55 percent of the variance in stock
announcement period returns is explained. The evidence is consistent with taxbased
theories of optimal capital structure, a positive debt level information
effect, and leverage-induced wealth transfers across security classes.
THERE IS AN EXTENSIVE theoretical literature concerning optimal capital structure.'
However, there is little empirical evidence of a relation between changes in
capital structure and firm value. In the best known test of an optimal capital
structure model, Miller-Modigliani [15] reported evidence of a positive relationship
between firm value and leverage which they attributed to a debt tax shield
effect. Their results are suspect, however, because of statistical problems they
encountered when attempting to adjust for differences in the firms' asset structures.
Since only regulated firms were examined, there is also some concern that
their empirical findings were caused by the regulatory environment in which
these firms operate. No strong evidence of a relation between a firm's value and
the size of its debt tax shield has been uncovered since the Miller-Modigliani
study.
This study estimates the impact of a change in debt level on firm values. Two
forms of capital structure change are examined: issuer exchange offers, and
recapitalizations. The results indicate that both stock prices and firm values are
positively related to changes in debt level and leverage; senior security prices are
negatively related to these capital structure change variables. This evidence is
consistent with models of optimal capital structure and with the hypothesis that
debt level changes release information about changes in firm value.