Elias Dinas and Kostas
Gemenis, "Measuring Parties' Ideological Positions With
Manifesto Data: A Critical Evaluation of the Competing
Methods," Party Politics, 16 (July, 2010), 427-450.
[Available at ]
First paragraph:
Positioning political actors (and political parties in
particular) along the Left-Right (L-R) continuum and other
policy dimensions has been an important feature of recent
empirical research in comparative politics. Based on a
variety of theories and methods, political scientists are
now 'able to operationalize a wide range of models within
what has become an important sub-discipline of political
science' (Laver, 2001a: 6). Three main approaches have been
proposed for the study of party location: (a) expert
surveys, (b) opinion poll data and (c) content analysis of
party manifestos.1 Although there is ongoing discussion
about the strengths and weaknesses of each approach (see
Budge, 2000; Kleinnijnhuis and Pennings, 2001; Mair, 2001;
McDonald et al., 2007; Steenbergen and Marks, 2007; Volkens,
2007), the last-mentioned has nevertheless become the most
popular for two reasons: first, data from party manifestos
attain a greater degree of impartiality. Expert surveys and
opinion poll data give us the picture of the party as
perceived by political analysts and voters, respectively.
Manifestos, on the other hand, provide a more accurate and
representative picture of where the parties stand in the
policy space, without our requiring further knowledge about
their policy record. Second, the Manifesto Research Group
(MRG, now renamed Comparative Manifestos Project, CMP) has
produced a rich time-series of data (see Budge et al., 2001;
Klingemann et al., 2007) that is unrivalled by any other
method. Consequently, the MRG/CMP approach has emerged as
the prima facie method by which to estimate parties' policy
positions against alternative data sources and also among
alternative methods of coding party manifestos.
Figures and
Tables:
Figure 1. Examining the scalability of the items
forming the right-wing indicators according to the
'standard' CMP method. Note: all items have been recoded,
ranging from 0 to 10
Figure 2. Examining the scalability of the items
forming the left-wing indicators according to the
'standard' CMP method.
Table 1. Reliability of the estimates according to
the Heise test-retest method
Figure 3. Greek parties' positions according to the
'standard' CMP method (Laver and Budge, 1992).
Figure 4. Greek parties' positions according to the
'vanilla' method (Gabel and Huber, 2000)
Figure 5. Greek parties' positions according to the
'two-stage factor-analysis' method (Laver and Budge,
1992)
Figure 6. Greek parties' positions according to the
'domestic' method (Klingemann, 1995)
Figure 7. Greek parties' positions according to the
'inductive' method (Laver and Budge, 1992)
Figure 8. Greek parties' positions according to the
'regression' method (Franzmann and Kaiser, 2006);
Table 2. Correlations among CMP estimates, expert
surveys and voters' perceptions
Last Paragraph:
(First paragraph of conclusion) If there is an answer to
this question, then it is probably not the standard CMP
method for the measurement of parties' positions in general
(Budge and Klingemann, 2001), or, in the case of Greece,
more specifically (Konstantinidis, 2004). Beyond that, to
argue that either the 'a-theoretical' 'vanilla method' or
the 'regression' method (which similarly relaxes the
'valence issue' assumption of CMP coding) performs better,
becomes a rather subjective and probably not very useful
enterprise. What is most important, however, is that by
analysing most of the employed methods in terms of their
reliability and validity, we find substantial divergence
between the methods. This finding questions the robustness
of results based on only one of the measures. Given that
there is no particular method that clearly outperforms all
others, it seems that it is pivotal for studies which employ
the CMP data to subject their analysis to sensitivity
testing.
