Bond of association
The (common) bond of association or common bond is the social connection among the members of credit unions and co-operative banks. Common bonds substitute for collateral in the early stages of financial system development. Like solidarity lending, the common bond has since played an important role in facilitating the development of microfinance for poor people. In modern financial systems, common bonds remain a key building block, especially for the strategic networks that underpin many of Europe’s co-operative banks. How bonds work. Hermann Schulze-Delitzsch, an early co-operative organizer, explained the concept of the  ‘bond of association’ at credit union meetings in this way: In his book "People’s Banks" (1910), Henry W. Wolff summarized the character of this ‘common bond’ based on his observations of credit unions all over Europe: Diverse types of bonds. There are several distinct types of bonds, corresponding to distinctive types of credit unions. For example: Debate between Schulze-Delitzsch and Raiffeisen. A bitter debate between two German credit union pioneers over the nature of bonds of association eventually ended in a tie, with Schulze-Delitzsch’s approach dominating in urban settings, and Raiffeisen’s dominating in rural ones . The bond of association for Schulze-Delitzsche’s larger, more urban ‘people’s banks’ required all members to contribute substantial share capital. He advocated that the banks should receive the protection of limited liability. Friedrich Wilhelm Raiffeisen strongly opposed any share capital requirement. Arguing that most farmers had too little cash to afford share capital, he maintained that the principle of unlimited joint liability was "indispensable in small districts". Instead, it was needed "in order to prevent the Unions from excess, since it makes the administrative bodies conscious of their moral and material responsibilities."