---
_id: '65066'
abstract:
- lang: eng
  text: "<jats:title>Abstract</jats:title>\r\n                  <jats:p>We investigate
    whether the recently approved reforms of the apportionment of parliamentary seats
    to parties in the German Bundestag affects the parties’ political influence measured
    by power indices. We find that under neither reform the underlying simple game,
    which describes the possibilities to form governments, remains unchanged and as
    a result the Shapley-Shubik and the Banzhaf index are unaltered. As a consequence,
    the major change resulting from the reforms is the reduction of the Bundestag’s
    size to 630 seats.</jats:p>"
article_type: original
author:
- first_name: Papatya
  full_name: Duman, Papatya
  last_name: Duman
- first_name: Claus-Jochen
  full_name: Haake, Claus-Jochen
  id: '20801'
  last_name: Haake
citation:
  ama: 'Duman P, Haake C-J. A Note on the Size Reduction Reform in the German Parliament:
    A Game Theoretic Analysis of Power Indices. <i>Review of Economics</i>. 2026;76(3):241-270.
    doi:<a href="https://doi.org/10.1515/roe-2024-0048">10.1515/roe-2024-0048</a>'
  apa: 'Duman, P., &#38; Haake, C.-J. (2026). A Note on the Size Reduction Reform
    in the German Parliament: A Game Theoretic Analysis of Power Indices. <i>Review
    of Economics</i>, <i>76</i>(3), 241–270. <a href="https://doi.org/10.1515/roe-2024-0048">https://doi.org/10.1515/roe-2024-0048</a>'
  bibtex: '@article{Duman_Haake_2026, title={A Note on the Size Reduction Reform in
    the German Parliament: A Game Theoretic Analysis of Power Indices}, volume={76},
    DOI={<a href="https://doi.org/10.1515/roe-2024-0048">10.1515/roe-2024-0048</a>},
    number={3}, journal={Review of Economics}, publisher={Walter de Gruyter GmbH},
    author={Duman, Papatya and Haake, Claus-Jochen}, year={2026}, pages={241–270}
    }'
  chicago: 'Duman, Papatya, and Claus-Jochen Haake. “A Note on the Size Reduction
    Reform in the German Parliament: A Game Theoretic Analysis of Power Indices.”
    <i>Review of Economics</i> 76, no. 3 (2026): 241–70. <a href="https://doi.org/10.1515/roe-2024-0048">https://doi.org/10.1515/roe-2024-0048</a>.'
  ieee: 'P. Duman and C.-J. Haake, “A Note on the Size Reduction Reform in the German
    Parliament: A Game Theoretic Analysis of Power Indices,” <i>Review of Economics</i>,
    vol. 76, no. 3, pp. 241–270, 2026, doi: <a href="https://doi.org/10.1515/roe-2024-0048">10.1515/roe-2024-0048</a>.'
  mla: 'Duman, Papatya, and Claus-Jochen Haake. “A Note on the Size Reduction Reform
    in the German Parliament: A Game Theoretic Analysis of Power Indices.” <i>Review
    of Economics</i>, vol. 76, no. 3, Walter de Gruyter GmbH, 2026, pp. 241–70, doi:<a
    href="https://doi.org/10.1515/roe-2024-0048">10.1515/roe-2024-0048</a>.'
  short: P. Duman, C.-J. Haake, Review of Economics 76 (2026) 241–270.
date_created: 2026-03-19T13:51:12Z
date_updated: 2026-03-19T13:56:59Z
department:
- _id: '205'
- _id: '475'
- _id: '200'
doi: 10.1515/roe-2024-0048
intvolume: '        76'
issue: '3'
jel:
- D72
- C71
keyword:
- Bundestag reform
- Banzhaf power index
- Shapley-Shubik power index
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.degruyterbrill.com/document/doi/10.1515/roe-2024-0048/html
oa: '1'
page: 241-270
publication: Review of Economics
publication_identifier:
  issn:
  - 0948-5139
  - 2366-035X
publication_status: published
publisher: Walter de Gruyter GmbH
quality_controlled: '1'
status: public
title: 'A Note on the Size Reduction Reform in the German Parliament: A Game Theoretic
  Analysis of Power Indices'
type: journal_article
user_id: '20801'
volume: 76
year: '2026'
...
---
_id: '34114'
abstract:
- lang: eng
  text: "Qualitative comparative analysis (QCA) enables researchers in international
    management to better understand how the impact of a single explanatory factor
    depends on the context of other factors. But the analytical toolbox of QCA does
    not include a parameter for the explanatory power of a single explanatory factor
    or “condition”. In this paper, we therefore reinterpret the Banzhaf power index,
    originally developed in cooperative game theory, to establish a goodness-of-fit
    parameter in QCA. The relative Banzhaf index we suggest measures the explanatory
    power of one condition averaged across all sufficient combinations of conditions.
    The paper argues that the index is especially informative in three situations
    that are all salient in international management and call for a context-sensitive
    analysis of single conditions, namely substantial limited diversity in the data,
    the emergence of strong INUS conditions in the analysis, and theorizing with contingency
    factors. The paper derives the properties of the relative Banzhaf index in QCA,
    demonstrates how the index can be computed easily from a rudimentary truth table,
    and explores its insights by revisiting selected papers in international management
    that apply fuzzy-set QCA. It finally suggests a three-step procedure for utilizing
    the relative Banzhaf index when the causal structure involves both contingency
    effects and configurational causation.\r\n"
article_type: original
author:
- first_name: Claus-Jochen
  full_name: Haake, Claus-Jochen
  id: '20801'
  last_name: Haake
- first_name: Martin
  full_name: Schneider, Martin
  id: '471'
  last_name: Schneider
  orcid: https://orcid.org/0000-0002-6961-3716
citation:
  ama: 'Haake C-J, Schneider M. Playing games with QCA: Measuring the explanatory
    power of single conditions with the Banzhaf index. <i>Journal of International
    Management</i>. 2024;30(2).'
  apa: 'Haake, C.-J., &#38; Schneider, M. (2024). Playing games with QCA: Measuring
    the explanatory power of single conditions with the Banzhaf index. <i>Journal
    of International Management</i>, <i>30</i>(2).'
  bibtex: '@article{Haake_Schneider_2024, title={Playing games with QCA: Measuring
    the explanatory power of single conditions with the Banzhaf index}, volume={30},
    number={2}, journal={Journal of International Management}, publisher={Elsevier},
    author={Haake, Claus-Jochen and Schneider, Martin}, year={2024} }'
  chicago: 'Haake, Claus-Jochen, and Martin Schneider. “Playing Games with QCA: Measuring
    the Explanatory Power of Single Conditions with the Banzhaf Index.” <i>Journal
    of International Management</i> 30, no. 2 (2024).'
  ieee: 'C.-J. Haake and M. Schneider, “Playing games with QCA: Measuring the explanatory
    power of single conditions with the Banzhaf index,” <i>Journal of International
    Management</i>, vol. 30, no. 2, 2024.'
  mla: 'Haake, Claus-Jochen, and Martin Schneider. “Playing Games with QCA: Measuring
    the Explanatory Power of Single Conditions with the Banzhaf Index.” <i>Journal
    of International Management</i>, vol. 30, no. 2, Elsevier, 2024.'
  short: C.-J. Haake, M. Schneider, Journal of International Management 30 (2024).
date_created: 2022-11-19T15:33:27Z
date_updated: 2024-04-24T12:58:51Z
department:
- _id: '205'
- _id: '475'
- _id: '178'
- _id: '185'
funded_apc: '1'
intvolume: '        30'
issue: '2'
keyword:
- Qualitative comparative analysis
- Banzhaf power index
- causality
- explanatory power
language:
- iso: eng
project:
- _id: '1'
  grant_number: '160364472'
  name: 'SFB 901: SFB 901'
- _id: '2'
  name: 'SFB 901 - A: SFB 901 - Project Area A'
- _id: '7'
  grant_number: '160364472'
  name: 'SFB 901 - A3: SFB 901 - Subproject A3'
publication: Journal of International Management
publication_status: published
publisher: Elsevier
quality_controlled: '1'
status: public
title: 'Playing games with QCA: Measuring the explanatory power of single conditions
  with the Banzhaf index'
type: journal_article
user_id: '20801'
volume: 30
year: '2024'
...