In the pecking order theory described by Myers (1984), there is no optimalcapital structure. To be more precise, if there is an optimum, the cost ofdeviating from it is insignificant in comparison to the cost of raising externalfinance. Raising external finance is costly because managers have moreinformation about the firm's prospects than outside investors and becauseinvestors know this. In Myers and Majluf (1984), outside investors rationallydiscount the firm's stock price when managers issue equity instead ofriskless debt. To avoid this discount, managers avoid equity whenever possible.The Myers and Majluf model predicts that managers will follow a peckingorder, using up internal funds first, then using up risky debt, and finallyresorting to equity. In the absence of investment opportunities, firms retainprofits and build up financial slack to avoid having to raise external financein the future.The pecking order theory regards the market-to-book ratio as a measure ofinvestment opportunities. With this interpretation in mind, both Myers (1984)and Fama and French (2000) note that a contemporaneous relationship betweenthe market-to-book ratio and capital structure is difficult to reconcilewith the static pecking order model. Iteration of the static version alsosuggests that periods of high investment opportunities will tend to pushleverage higher toward a debt capacity. To the extent that high past marketto-book actually coincides with high past investment, however, our resultssuggest that such periods tend to push leverage lower.15