Strebulaev A. Ilya (2007) discussed in
article that optimal capital structure research based on regularities in the
cross section of leverage to discriminate between various theories of financing
policy. Researcher use book and market leverage and develop relationship with
profitability, book to market and firm size. Changes in market leverage are
largely explained by changes in equity value. Past book to market rations help
to predict current capital structure. Firms use debt financing conservatively,
and leverage of stable and profitable firms appears low. Even if firms have
target leverage ratio they slowly moved toward it.