A center-left coalition may emerge after the new elections in Germany

The upcoming Federal elections in Germany on September 26, 2021 will determine the successor of Angela Merkel, the outgoing Chancellor of the Federal Republic and the leader of the Christian Democratic Union (CDU). The CDU/CSU block has retained a leading position in government for almost 16 years but is quickly losing support in the post-Merkel era. As a consequence, the possibility of a new coalition that excludes the Union can no longer be discounted.

The Social Democratic Party of Germany (SPD) has demonstrated a notable gain in electoral support in recent months, while CDU/CSU and the Greens have lost ground. The decreasing popularity of CDU/CSU can be attributed to various factors. Some voters have been dissatisfied with the handling of the COVID-19 crisis, while others appreciated a more central political position of CDU/CSU under Angela Merkel’s leadership. Further criticism has been expressed concerning the response to the floods in Germany in July of 2021.

We base our forecast on the poll data (INSA, 6-10.09.2021) , and assess the stability of alternative majority coalitions subject to compatibility constraints among their members. Specifically, we assume that no party besides the CDU/CSU would partner with the right-wing Alternative for Germany (AfD).

Constraints in coalition formation
Projected seats (bar size) vs. strategic influence (Shapley value) of political parties (red lines)
Stability (white bars) of predicted majority coalitions

The coalition with greatest stability is projected to be SPD-Left-Green, immediately followed by CDU/CSU-FDP-Green. This remains the case under the additional assumption that an alliance with the Left with CDU/CSU or FDP is excluded.

A coalition of CDU/CSU and SPD will continue to have a majority, however, neither of the parties is expected to favor this scenario, as they would be likely to enjoy a more dominant role in a coalition that excludes the other. A coalition consisting of SPD, FDP, and the Greens is likewise likely to be unattractive for potential participants due to a broader range of political platforms.