Oxford University Comparative Law Forum
The Adjudication of the German Federal Supreme Court
(BGH) in the Last 55 Years - A Quantitative and Comparative Approach
Mathias M. Siems*
(2007) Oxford U Comparative L Forum 4 at ouclf.iuscomp.org | How to cite this article
Table of contents
Today, many law journals can be accessed electronically. This is not
only convenient but it also offers the interesting possibility of a
quantitative analysis. In the US, this is already quite common,1 and there
is no reason why this should not also be pursued in other countries.2 It is true
that the mere counting of particular words could be regarded as
superficial because this does not consider the specific context in
which a word is used. However, some reduction of complexity is inherent
to all quantitative methodologies, without implying that it is not
feasible to pursue them.3
Moreover, quantitative methodology has the advantage that - in
accordance with the scientific method4 - it can be used to test hypotheses
This short article employs quantitative methodology in order to
analyse the adjudication of the German Federal Supreme Court (Bundesgerichtshof,
BGH). It considers all decisions of the BGH which have been
published in the major German law journal NJW (Neue
Juristische Wochenschrift) between 1951 and 2006.5 In total, this concerns
27,562 decisions. As the number of decisions which are reported in the NJW
slightly varies per year, the following figures do not show the
absolute numbers per year but the hits per hundred decisions.6
A future piece will also provide comparable data for the United
Kingdom. For a comparison, the present article will limit itself to
formulating some hypotheses as to whether comparable data relating to
UK jurisprudence should be expected to yield similar or different
II. Citation to Other Court Decisions
The number of citations to other decisions does not reveal whether a
court approved or disapproved these decisions. Nonetheless, this number
is interesting because it indicates the degree to which previous
decisions have potentially influenced a court.
1. Citation to other courts
The German Federal Supreme Court (BGH) is the highest court
in matters of private and criminal law, which also includes civil and
Only when constitutional issues arise within a particular case decided
by the BGH, a further constitutional complaint to the German
Federal Constitutional Court (BVerfG) may lead to the BVerfG
repealing a decision made by the BGH. A similar hierarchy
exists between the BGH and the European Court of Justice (ECJ),
because the case law of the ECJ is only relevant for the BGH if
it decides about a topic which is related to a provision of the
European Treaty or secondary community law.9 Foreign court decisions
have no formal authority in German courts (unless relating to a matter
governed by foreign law). However, it is accepted that insights gained
from a comparative legal analysis may be brought in as a cognitive
approach in interpreting German law.10
Figures 1a displays how often the BGH has cited to decisions
by the German Federal Constitutional Court and by the European Court of
Justice. It can be observed that the citations to the German Federal
have constantly increased. On the one hand, this could be expected
because the German Federal Constitutional Court was only established in
1949, and therefore there was little case law which could have been
cited to by the BGH in the 1950s. On the other hand, one may
still be surprised about the extent of citations. In 2004, about 18 per
cent of the BGH's decisions mentioned the German Federal
Constitutional Court. It can therefore be concluded that there is a
growing 'constitutionalization' of private and criminal law. Examples
would be legion. For instance, in private law, human rights have often
been used in order to protect the weaker party of a contract (e.g., in
cases of spousal guarantees12). With respect to criminal law,
likely main reasons are those principles of criminal law which enjoy
constitutional status, such as that there must not be a crime or
punishment without the law (nullum crimen sine lege; nulla poena
When a case involves such constitutional principles, the German Federal
Constitutional Court may rectify evident mistakes made by of criminal
courts. Finally, procedural law has a constitutional dimension. The
German constitution contains at least three provisions which require
fairness in court proceedings.14 Thus, the German Federal
Constitutional Court adjudicates on procedural questions, which
subsequently makes the BGH cite the German Federal
Decisions of the European Court of Justice have also increasingly
On the one hand, this too is just a consequence of the fact that
previously there were no or less decisions which could have been cited.
On the other hand, the increase is a result of the growing quantity of
European directives and regulations as well as the expansion of the
European Treaty in 1987, 1993 and 1999.16 As a consequence, in 2006 about 6
per cent of the decisions of the BGH refer to the European
Court of Justice. This is still well below the citations to the German
Federal Constitutional Court, but it remains to be seen how this will
develop in the future.
Figure 1b demonstrates how often the BGH has cited the
Austrian and Swiss supreme courts17 as well as other foreign supreme
The result is that there have been 66 references to the former and 64
references to the latter courts. A quantitative analysis cannot examine
in which context these foreign decisions have been mentioned. It is
possible that some cases have used comparative insights in order to
address a problem of domestic substantive law. Yet, when taken
together, probably more cases have referred to foreign decisions in
questions relating to the application of that foreign law, or of
private international law, jurisdiction, and uniform international law
(e.g., CISG). Regardless of this problem, the overall result is that,
pro rata, few decidsions refere to foreign courts. This negative
finding is in line with previous research which also found that courts
rarely use comparative law.19 This reluctance is hardly
surprising. Courts often lack the knowledge and the time to take
comparative arguments into account. Moreover, there may be reasons
based on national sovereignty, which was recently vividly emphasised by
some of the judges of the American Supreme Court.20
2. Citation of own decisions
It is also interesting to examine how often and when the BGH
cites to its own decisions. Figure 2 shows how frequently the decisions
of the volumes 10 (1953), 50 (1968), 100 (1987), and 140 (1998) have
been cited. The general shape of all four curves is that there are
initially no citations, then a steep rise, and finally a smooth
decline. A possible explanation for these developments is that after a
first 'excitement' about new decisions, subsequent decisions or law
reforms may modify or even reverse their findings. Additionally, it is
likely that the decline over time is the result of the fact that if
there is a series of similar decisions German courts usually cite the
most recent decision only and add 'm. w. N.' ('mit weiteren
Nachweisen'), which means 'with further references'. Thus, in these
situations the original decision is still 'good law' but 'falls victim'
of a shorthand citation.
Comparing the four curves, it is, first, noticeable that the initial
rise is very steep for the two later volumes (BGHZ 100 and 140),
whereas for the two earlier volumes (BGHZ 10 and 50) it took a few
years until the peak of citations was reached. This is likely to
reflect the fact that the speed of communication has improved in the
last decades, because, for instance, there are now more law journals
which discuss the case law of the BGH. Secondly, one may wonder
why the 'BGHZ 100 curve' reached a significantly higher peak than the
other three curves. This could just be a coincidence. Another slightly
frivolous - but still plausible - explanation could be that judges like
to cite the 'jubilee volume BGHZ 100'. Since in Germany the names of
the parties are not disclosed in the judgments, only the volumes and
page numbers are cited. Thus, it may indeed be the case that judges
more easily remember a decision in 'BGHZ 100' than, for instance, in
3. Comparative remarks
In general, similar data can also be collected for the United
Kingdom. However, it may be difficult to achieve full comparability
with the citations of the BGH. For instance, there is no
distinction between a constitutional court and a supreme court in the
UK. Thus, data about decisions of the House of Lords may, to some
extent, concern different subject matters than the data about the
decisions of the BGH.
To elaborate for Figure 1, it is not possible to examine the
citations to a constitutional court in the UK. However, an analogy may
be that it can be counted how often the House of Lords has cited the
European Court of Human Rights. One could expect that since the Human
Rights Act 1998 (in force since 2000) the number of citations has
grown. With respect to citations to the European Court of Justice, the
situation may be similar to Germany, and therefore a rising curve may
also be likely for the UK. Finally, in contrast to Germany, a trend may
also be expected for the citation to foreign courts. Citing to courts
of other common law countries has a certain tradition, but since the
decision in White v Jones21 there have been a number of
prominent cases in which the House of Lords has also referred to
continental legal systems.22
With respect to Figure 2, the shape of the curves may be similar
but not identical in Germany and the UK. In general, it is probably
also the case in the UK that new decisions receive particularly strong
attention. However, there may also be differences. Despite the growing
importance of statutory law, case law is presumably still more
important in the UK than in Germany. For a system of case law it may be
likely that old court decisions are more honoured than in the civil law
world. It is therefore possible (or even likely) that the 'half-life
period' of court decisions is longer in the UK than in Germany.
A final point which needs to be considered is that Scottish cases
decided by the House of Lords may display special features. As Scotland
is a mixed legal system, one may, for instance, expect that references
to court decisions of civil law countries or of other mixed legal
systems (such as South Africa) are more common than in other decisions
of the House of Lords.
III. Legal Methodology
The next figures show how often specific words which relate to legal
methodology have been mentioned in decisions of the BGH. This
approach has some obvious inherent limits. In some cases, the BGH
may use a particular methodology without mentioning the specific word.
For instance, the BGH may take the history of a particular
provision into account without using the German equivalents of the
terms 'history' or 'legal history' (cf. Figures 3 and 5 below).
Nevertheless, it is interesting to examine how often a particular
methodological term has been expressly mentioned, because in
these cases the methodological concept is likely to be particularly
1. Methods of interpretation
Figure 3 relates to the four German 'classic methods of legal
interpretation'. The predominant view is that there is no ranking of
these four methods but the interpretation of a particular statutory
provision has to try to accommodate all of them.23 However, the
statistical breakdown reveals significant differences between the
actual use of terms relating to particular methods. The BGH
most frequently refers to 'wording', then to 'purpose', and at the
bottom end, we find 'history' and the 'systemic context' of a provision.24 The
frequent emphasis of wording may indicate some formalism - or it may
just be that it is often the easiest way to stick to the literal
interpretation. Conversely, an interpretation based on the history or
the systemic context is more burdensome and therefore perhaps less
The development of these four curves also shows some interesting
features. Only the 'purpose' has been relatively stable whereas
references to 'wording' and 'system' have increased, and references to
'history' have decreased. A possible explanation for the increases in
the importance of 'wording' and 'system' is that the German legal
system has become increasingly complex. Thus, judges may either prefer
'the easiest path' and just stick to the wording of a particular
provision, or they may try to establish how a particular provision has
to be understood within the complexities of the legal system as a
whole. The slow decline of historical arguments can presumably be based
on the consideration that today judges regard it as less necessary to
examine the history of the 'big old codes',25 which initially came
into force in 1900.
2. Flexibility and tradition
The frequency of 'analogy' may indicate the degree to which judges
are willing to be flexible, by disregarding the narrowness of a
particular provision and extending its scope by an argument of analogy.
Increased flexibility may thus offer one explanation for Figure 4,
which shows a very significant increase in the percentage of decisions
which refer to 'analogy'.26
However, the better explanation may be that decisions of the BGH
not only create some new analogies but also confirm the existing ones.
Thus, all that can be deduced from Figure 4 with reasonable certainty
is that the total number of analogies has been growing.
In Germany it is very common that judges (and other lawyers) refer
to 'the predominant view', as a shorthand for a wide ranging agreement
between courts and scholars on a particular legal issue which attracts
no or few voices of dissent. It may be expected that in the course of
time this has become even more frequent because more and more topics
have been settled. However, the inconsistent shape of the curve in
Figure 4 does not confirm this expectation.27 A likely explanation
is that at the same moment when some views become dominant new problems
and puzzles emerge. This curve therefore shows that the legal system is
and that it will not reach a point when everything will be beyond
3. Foundations of the law
In contrast to the previous figures, Figure 5 does not show the hits
per hundred decisions but the absolute numbers of hits. This
representation was chosen because of the very low occurrence of any of
the search terms, which were close to 0 per cent for all the terms
shown in Figure 5. The first result of Figure 5 is therefore that the BGH
hardly ever uses the terms 'legal sociology', 'legal history', 'legal
philosophy', 'legal theory', 'comparative law', and 'legal methods'.29 There
are few or no citations to the first four terms, and only rarely are
there references to books about comparative law and legal methods.
Secondly, it is also remarkable that this has not changed in recent
years. In the US, Richard Posner declared 'the decline of law as an
autonomous discipline' 20 years ago,30 and it was also said that the 21st
century is to be 'era of comparative law'.31 Yet, a quantitative
analysis of the adjudication of the BGH does not confirm these
4. Comparative remarks
The main challenge of this part was to find terms which are
meaningful indicators of a particular methodology. In this respect, it
is the same problem in Germany and the United Kingdom that courts may
use a particular method without explicitly mentioning it. However,
there are different problems in both countries.
With respect to Figure 3, it is perhaps easier in the United
Kingdom than in Germany to collect data about the general methods of
statutory interpretation. The reason for this is that one can search
for specific terms and not merely 'wording', 'history' etc. For
instance, the 'literal rule', the 'golden rule', and the 'mischief
rule' are the traditional formal rules of interpretation, which in the
last years have (allegedly) become weaker in favour of a more purposive
This can be tested by searching for the former terms. Conversely, it is
possibly less reliable to search for 'purposive interpretation',
because courts may frequently consider the purpose of a provision
without explicitly mentioning this term. A second trend which one would
expect is that since 1993 references to 'Hansard' - the official report
of Parliamentary proceedings - have increased, because the possibility
of referring to it was only allowed by the landmark decision of Pepper
Furthermore, it would be interesting to see whether in the last few
years there has been a quantifiable retreat from Pepper v Hart,
as it was recently suggested.34
Figure 4, which counts '(legal) analogy' and 'predominant view',
would be problematic because the dichotomy between flexibility and
tradition works differently in the UK. It is the very feature of a
system which relies to a greater extent on case law that it combines
both elements. On the one hand, case law is flexible because it is not
restrained by comprehensive statutory law. On the other hand, case law
is also conservative because it relies on judicial precedents. Thus,
one has to find a different method in order to establish whether the
adjudication has become more or less flexible in the UK. A possible
(but not perfect) way could be to count how often the House of Lords
has expressly used terms like 'justice' or 'fairness'.35
With respect to Figure 5 there would presumably be very few (if
any) hits of the terms 'legal sociology', 'legal philosophy', 'legal
methods' etc. in decisions of the House of Lords. The main reason for
this is that references to academic books and articles are (still) very
rare in the UK, which, of course, does not exclude that in substance
academic approaches to law have become more influential.36
Finally, it would again be important to examine whether Scottish
cases decided by the House of Lords may display special features. At
first sight the legal methodology between Scotland and the rest of the
UK appears to be relatively similar.37 However, there may also be
differences. For instance, in Scottish cases - even if they are decided
by the House of Lords - there may be a more 'civilian' way of
referencing, for instance, to legal writings,38 and less reliance on
case law only.
IV. Summary and Outlook
Quantitative methods are no panacea and have inherent limits.39
However, they can also lead to interesting results. For instance, a
quantitative analysis of the adjudication of the German Federal Supreme
Court (BGH) suggests (1) that there has been a growing
'constitutionalisation' and Europeanisation of private and criminal
law; (2) that decisions of foreign courts have usually been disregarded
by the BGH; (3) that the BGH prefers to cite recent
decisions; (4) that the speed in which decisions are communicated has
improved; (5) that the BGH more often emphasises the wording of
a particular provision than the other methods of legal interpretation;
(6) that references to systemic arguments have become more, and
references to legal history less frequent; (7) that the total number of
analogies has been growing; (8) that it is common (but not growing)
that the BGH refers to 'the predominant view'; (9) and that
references to the terms 'legal sociology', 'legal history', 'legal
philosophy', 'legal theory', 'comparative law', and 'legal methods'
have been very seldom in the decisions of the BGH.
A future study will extend this examination to the United Kingdom.
This article already indicated that for some topics - for instance, (2)
and (3) - different results may be expected, and that other topics -
for instance, (7) and (8) - have to be examined with a different
Reader in Commercial Law, University of Edinburgh; Research Associate,
University of Cambridge. I am grateful for comments made by Gerhard
Dannemann, Jill Robbie and Burkhard Schäfer. The usual disclaimer
See e.g. Robert C. Ellickson, 'Trends in Legal Scholarship: A
Statistical Study', (2000) 29 Journal of Legal Studies 517;
Richard A. Posner, Frontiers of Legal Theory (2001) 411-440;
Alfred Brophy, 'Law [Review]'s Empire: The Assessment of Law Reviews
and Trends in Legal Scholarship', (2006) 39 Connecticut L Rev 101.
rare example from Germany is Roland Wagner-Döbler and Lothar
Philipps, 'Die Verbreitung neuer Rechtsbegriffe in der Rechtsprechung.
Quantitative Analysen anhand deutscher Urteilstexte aus den Jahren 1950
bis 1992', (1995) 26 Rechtstheorie 235.
See also Mathias M. Siems, 'Numerical Comparative Law: Do We Need
Statistical Evidence in Order to Reduce Complexity?', (2005) 13 Cardozo
J of Int and Comparative L 521, Priya Lele and Mathias M. Siems,
'Shareholder Protection - A Leximetric Approach', (2007) 7 J of
Corporate L Studies 17; Mathias M. Siems, 'Statistische
Rechtsvergleichung', Rabels Zeitschrift für ausländisches und
internationals Privatrecht (forthcoming).
See e.g. Sir Karl Popper, The Logic of Scientific Discovery
(1959) and Objective Knowledge (1972); see also Mathias M.
Siems, 'Legal Originality' (Working Paper, 2006), available at
Available at http://www.beck-online.de
(but password required).
With the exception of Figure 5, below.
See I 3 and II 3, below.
There are four other supreme federal courts: The Federal Administrative
Court (BVerwG), the Federal Finance Court (BFH), the
Federal Labour Court (BAG), and the Federal Social Court (BSG).
See Art. 95 of the German Basic Law (Grundgesetz). The Federal
Constitutional Court (BVerfG) and the Federal Patent Court (BPatG),
while also federal courts, do not act as supreme courts for any branch
Details about the complex relationship between national and community
law are beyond the scope of this article.
See Hein Kötz, Der Bundesgerichtshof und die Rechtsvergleichung, Festgabe
50 Jahre Bundesgerichtshof, Volume II (2000), 825.
Search for 'Bundesverfassungsgericht' or 'BVerfG'.
See e.g. Mathias M. Siems, 'No Risk, No Fun? Should Spouses be Advised
before Committing to Guarantees? A Comparative Analysis', (2002) 10
European Rev of Private L 509; Olha Cherednychenko, 'The
Constitutionalization of Contract Law: Something New Under the Sun?',
Electronic J of Comparative L, Vol. 8.1 March 2004, available at http://www.ejcl.org/81/art81-3.html.
See Art. 103(2) of the German Basic Law (Grundgesetz).
See Art. 19(4) ('Should any person's rights be violated by public
authority, he may have recourse to the courts'), Art. 20(3) ('The
legislature shall be bound by the constitutional order, the executive
and the judiciary by law and justice'), and Art. 103(1) ('In the courts
every person shall be entitled to a hearing in accordance with law.')
of the German Basic Law (Grundgesetz) as translated at http://www.bundestag.de/htdocs_e/parliament/function/legal/germanbasiclaw.pdf.
Search for 'Europäischer Gerichtshof' or 'EuGH'.
Single European Act 1976; Treaty of Maastricht 1993; Treaty of
Search for 'österr. OGH', 'öst. OGH', 'öster. OGH',
'österreichische OGH', 'österreichische Oberste Gerichtshof',
'öst. Oberste Gerichtshof', 'OGH and österreich*', 'Schweizer
Bundesgericht', 'schweizerisches Bundesgericht', 'Schweiz.
Bundesgericht', 'Schweizer BG', 'schweizerisches BG', 'Schweiz. BG',
'BG and Schweiz*', or 'Bundesgericht and Schweiz*'. This complex search
list was necessary in order to exclude citations to German courts.
Search for 'Supreme court', 'House of Lords', 'Court of Appeal', 'Cour
de Cassation', or 'Kassationsgerichtshof'.
Ulrich Drobnig and Sjef Van Erp (eds), The Use of Comparative Law
by Courts (1999); Hein Kötz, 'Der Bundesgerichtshof und die
Rechtsvergleichung', in Festgabe 50 Jahre Bundesgerichtshof, Volume
II (2000) 825. See also Sir Basil Markesinis and Jörg Fedtke,
'The Judge as Comparatist', (2005) 80 Tulane L Rev 11; Sir Basil
Markesinis and Jörg Fedtke (eds.), Judicial Recourse to
Foreign Law (2006); Mathias M. Siems, 'The End of Comparative Law',
(2007) 2 The J of Comparative L (forthcoming).
Lawrence v Texas 123 Ct 2472, 2495 (2003) (Scalia J) and Foster
v Florida, 537 US 990 (2002) (Thomas J): 'this Court [...] should
not impose foreign moods, fads, or fashions on Americans'. For further
examples see Pierre Legrand, 'Comparative Legal Studies and the Matter
of Authenticity', (2006) 1 J of Comparative L 365; Toni Fine, 'American
Courts and Foreign Law: The New Debate' (2006) DAJV Newsletter
 2 AC 207 (HL).
See the cases cited in Sir Basil Markesinis and Jörg Fedtke, 'The
Judge as Comparatist', (2005) 80 Tulane L Rev 11, at 31-2.
Cf. e.g. Karl Larenz and Claus Wilhelm Canaris, Methodenlehre der
Rechtswissenschaft (3rd edn., 1991) 141 et seq. For a comparative
account see Stefan Vogenauer, Die Auslegung von Gesetzen in England
und auf dem Kontinent (2001).
Search for (1) 'Wortlaut*', (2) 'Systemati*', (3)
'Entstehungsgeschicht*' or 'Geschicht*', and (4) 'Sinn und Zweck' or
'teleologi*'. In some cases these words may also refer to the
interpretation of contracts. However, this concerns only a small
minority of hits. For instance, out of a random sample of 20 decisions
which referred to "Wortlaut" only one of them did not concern statutory
Civil Code, BGB; Commercial Code, HGB; Code of Civil
Procedure, ZPO; Criminal Code, StGB; Code of Criminal
Search for 'Analog*' or 'Rechtsfortbildung'.
Search for 'herrschende* Lehre', 'herrschende* Literatur',
'herrschende* Meinung', 'herrschende* Ansicht', 'allgemeine* Ansicht',
'allgemeine* Meinung', 'herrschende* Rechtsprechung' or 'allgemeine*
See also Simon Deakin, 'Evolution for our time: a theory of legal
memetics', (2002) 55 Current Legal Problems 1.
Search for 'Rechtsvergleichung', 'Rechtsgeschichte',
'Rechtsphilosophie', 'Rechtstheorie', 'Methodenlehre',
Richard A. Posner, 'The Decline of Law as an Autonomous Discipline:
1962-1987', (1987) 100 Harvard L Rev 761.
Esin Örücü, The Enigma of Comparative Law (2004)
216; Tim Koopmans, 'Comparative Law and the Courts' (1996) 45 ICLQ 545,
556. For a different view see Siems (n. 19).
For a brief description see e.g. Michael Zander, The Law-Making
Process, 6th edn (2004), pp. 130-149.
 AC 593,  3 WLR 1032,  1 All ER 42 (HL).
Stefan Vogenauer, 'A Retreat from Pepper v Hart? A Reply to Lord Steyn'
(2005) 25 Oxford Journal of Legal Studies 629.
See for example White v Jones  2 AC 207 at 259 per Lord
Goff: 'The impulse to do practical justice'.
For this point see Vogenauer (n. 23), pp. 1212-1214.
See e.g. Robin M. White and Ian D. Willock, The Scottish Legal
System, 3rd edn (2003), p. 259 (on Pepper v. Hart), pp. 263-265 (on
the 'literal rule', the 'golden rule', and the 'mischief rule').
In particular the institutional writers and their successors. For an
introduction see Hector L. MacQueen, Studying Scots Law, 3rd
edn. (2004), paras. 1.47-1.48.
See 1., above.
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