According to the German Federal Constitutional Court (Bundesverfassungsgericht), the legislature is under a constitutional obligation to enact only coherent and consistent laws. This principle of legislative consistency (Folge richtigkeit) is accorded different roles within
the fundamental rights juris prudence of the Court. In the context of the constitutional guarantee of equality, an inconsistent law can be regarded as an indication for an unequal treatment and can lead to stricter standards of scrutiny. The Constitutional Court, furthermore, attributes particular
significance to the principle of legislative consistency within the context of tax laws and electoral laws. A closer analysis, however, leads to the conclusion that the principle of legislative consistency does not enhance the rationality of the Constitutional Court's equal rights jurisprudence.
First, there are no generally accepted and convincing standards to determine whether a law is consistent or not and whether a certain statutory rule is part of or contrary to a legislative system. Second, there is no compelling reason to assume that inconsistent laws necessary entail an unequal
treatment and lead to inequality. Within the context of tax laws and electoral laws, the principle of legislative consistency is even more problematic since it disguises the appropriate standard of constitutional review, which should be equal protection and not systemic coherence. Beyond
the Constitutional Court's equal rights jurisprudence, the principle of legislative consistency has gained significance in the context of constitutional liberties. In a 2008 decision, the Court held that an inconsistent legislative act can influence the proportionality analysis that oftentimes
lies at the heart of a constitutional rights case: If the legislature pursues a specific goal in an inconsistent manner, this lowers its weight within the process of balancing competing interests. While this ruling of the Court has been fiercely criticized, a closer analysis reveals that the
Court's approach is in line with the previous and generally accepted jurisprudence with regard to proportionality analysis. Moreover, it has to be understood as a logical consequence of the very concept of proportionality which requires balancing of competing interests. In light of this, however,
the idea of legislative consistency does not have any significance as an independent doctrinal concept but rather describes the process of evaluating the competing interests that have to be balanced in the course of proportionality analysis. As a result, the principle of legislative consistency
should be abandoned as a doctrinal concept of constitutional law. The German Constitution does not establish a general obligation of the legislature to enact only consistent laws. The principle of legislative consistency does not rationalize the fundamental rights discourse and is unsuitable
as a standard of constitutional review. Moreover, whenever the Constitutional Court declares a legislative act to be void due to a violation of the principle of legislative consistency, the Court exposes itself to the criticism that it has overstepped its boundaries and illegitimately encroached
upon the competences of the legislative branch.