This paper surveys capital structure theories based on agency costs, asymmetric information,
product/input market interactions, and corporate control considerations (but excluding
tax-based theories). For each type of model, a brief overview of the papers surveyed
and their relation to each other is provided. The central papers are described in
some detail, and their results are summarized and followed by a discussion of related
extensions. Each section concludes with a summary of the main implications of the
models surveyed in the section. Finally, these results are collected and compared
to the available evidence. Suggestions for future research are provided.