ABSTRACT
Maurice Duverger, in classifying parties by membership, noted three types: the decentralized caucus party, with few members; the party based on cells and militias, with a fanatical mass membership; and the party based on branches, with many members, representing a middle ground in party solidarity between the first two types. The statute notes that membership is open to any person over sixteen who acknowledges the basic principles of the party. Membership ends through death, resignation, or expulsion. A ground for expulsion, which needs an arbitration commission approval, is simultaneous membership in another political party or in an organization that the party’s executive and council have deemed incompatible with Social Democratic Party goals. Membership in the party has fluctuated considerably over the decades. During the Empire era it reached 1,086,000 in 1914, and in the Weimar era it ranged from a high of 1,261,000 in 1923 to a low of 806,000 in 1926.
