The Social Democratic Party was one of the original parties in Janda's 1950-1962 ICPP study. The party continued throughout 1950-1990 in the Harmel-Janda study of party change.

The essay on party politics in West Germany from 1950 to 1962 says:

After moderating its socialist program in 1959, the SPD steadily increased its legislative representation until it was able to form its own coalition government with the FDP in 1969 under Willy Brandt as chancellor. The coalition held together through elections in 1972, through Brandt's resignation is chancellor and the succession of Helmut Schmidt, and through the close elections of 1976.

The essay on party politics in the united Germany from 1963 to 2000 says:

SPD, was a re-creation of a former labor-oriented party of the same name which had been outlawed by the Hitler regime in 1933. It made a comeback after WWII, controlling the government from 1969 until 1982 in a coalition with the FDP. In 1982, their government, under the leadership of Helmut Schmidt, collapsed and lost the chancellorship in the election of 1983. The SPD did not regain control of government until the 1998 election.

Consult the index to variables for annual scores of the party's issue orientation, organizational complexity, centralization of power, and coherence from 1950 through 1990.