SMEs often have to face restricted access to bank loans. This is particularly due for those SMEs that cannot provide enough valuable collateral. By underwriting a certain share of the overall risk of the loan amount, German guarantee banks facilitate the access to bank finance of SMEs with no or not enough valuable collateral. To justify this governmental intervention, guarantee banks need to be evaluated regularly. This book presents a unique research approach to evaluate the impact of German guarantee banks on the access to bank finance for SMEs by testing the ability of guarantee banks to compensate collateral shortfalls and make available loans to SMEs. Moreover, this book extends existing literature by analysing the ability of guarantee banks to reduce information asymmetries, create lending relationships and mitigate credit restrictions immediately as well as in a sustainable way. This analysis should be especially useful for policy makers, bank managers deciding about granting loans to SMEs, and for SMEs to learn about possibilities to mitigate credit restrictions.