Method: Case Study

.title[
# Method: Case Study
]
.subtitle[
## Public Policy Analysis: Perspectives and Methods (30700953)
]
.author[
### Yue HU
]

---

## Overview

1. What's a case?
1. Case selection
1. Case comparison
1. Mixed method

---

# Case

---

## What's a Case?

A unit that contains a series of events or a number of elements.

Boundary of a Case:<sup>\*</sup>

+ Spatial
+ Temporal
]

1. One unit over time
1. N subunit at one time
1. N subunit over time
]

---

## An Observation, Variable, Case?

<table class="table table-responsive" style="font-size: 25px; margin-left: auto; margin-right: auto;">
 <thead>
  <tr>
   <th style="text-align:center;"> Observed </th>
   <th style="text-align:right;"> Party </th>
   <th style="text-align:right;"> Region </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:center;"> 1 </td>
   <td style="text-align:right;"> Party Member </td>
   <td style="text-align:right;"> Educational </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 2 </td>
   <td style="text-align:right;"> Non-PM </td>
   <td style="text-align:right;"> Educational </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 3 </td>
   <td style="text-align:right;"> Party Member </td>
   <td style="text-align:right;"> Educational </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 4 </td>
   <td style="text-align:right;"> Non-PM </td>
   <td style="text-align:right;"> Educational </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 5 </td>
   <td style="text-align:right;"> Party Member </td>
   <td style="text-align:right;"> Dependents </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 6 </td>
   <td style="text-align:right;"> Non-PM </td>
   <td style="text-align:right;"> Dependents </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 7 </td>
   <td style="text-align:right;"> Party Member </td>
   <td style="text-align:right;"> Dependents </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 8 </td>
   <td style="text-align:right;"> Non-PM </td>
   <td style="text-align:right;"> Dependents </td>
  </tr>
</tbody>
</table>

---

## What's a Case Study

> An intensive study of a .red[single unit] for the purpose of understanding a larger class of (similar) units  
 ---Gerring (2004: 342).

???
Gerring, John. 2004. “What Is a Case Study and What Is It Good For?” American Political Science Review 98(2): 341–54.

---

## Five Strengths of Case Studies

1. .blue[Deep] rather than .red[broad, bounded scope] of proposition

1. .blue[Mechanism] rather than .red[effect]

1. .blue[Deterministic] rather than .red[probabilistic] relations

1. .blue[Exploring] rather than .red[confirmatory] test

---

## Representation of a Case

Should we randomly pick a (or several) case for a case study?
- Yes, why?
- No, why not?

5\. .blue[Understanding] rather than .red[representing] other cases

???

a representative case from test, a random sample of comparative group in tenure

Representativeness roots from large-N analysis

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# Case Selection

---

## Principle of Case Selection

Minimizing .red[selection bias]

???

No! Not representative

---

## Different Selection, Different Consequences

???

Select X

---

???

Select Y

---

???

Select XY

---

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## Case Selection Criteria

???

Van Evera, Stephen. 1997. *Guide to Methods for Students of Political Science*. 1 edition. Ithaca: Cornell University Press.

1. Data richness;

???

COVID-19 in North Korea

twitter in China

1. Extreme values;

???

Most likely case: patriotism in the Internet
Least likely case: 摆烂 in Tsinghua

1. Large within-case variance;

???

U.S. state politics

Turkey, Iran: temporary changes

1. Divergence of predictions based on theory;

???

What will Russia-Ukraine case go

See the examples later

1. Resemblance of case background conditions to the conditions of  current policy problems;

???

Case travel less widely overall but more widely to important circumstances

Legal case

Roe and Casey case that supreme court intend to overwrite

The decision involved the case of Norma McCorvey—known by the legal pseudonym "Jane Roe"—who in 1969 became pregnant with her third child. McCorvey wanted an abortion but lived in Texas, where abortion was illegal except when necessary to save the mother's life. Her attorneys, Sarah Weddington and Linda Coffee, filed a lawsuit on her behalf in U.S. federal court against her local district attorney, Henry Wade, alleging that Texas's abortion laws were unconstitutional. A three-judge panel of the U.S. District Court for the Northern District of Texas heard the case and ruled in her favor. Texas then appealed directly to the U.S. Supreme Court.

Shanghai, hefei Covid 19

1. Prototypicality of case background conditions;

???

Case can "travel" widely

亚非拉

1. Outlier character;

???

The U.S., Singapore

1. Intrinsic importance;

???

COVID-19, governance, metaverse, hot topics

1. Appropriateness for replication of previous tests

???

清河实验

1928年，燕京大学社会学家杨开道、许世廉等人就曾在这里做过一次著名的“清河实验”。他们在农村社区培养有威望的社区领袖，增强农民的自我组织能力，从经济、社会等多方面提出改良措施，为乡村振兴树立了优秀典范。

随着抗战爆发，持续9年的老“清河实验”被迫中断。数十年的岁月改变了清河的样貌，聚焦公众参与的社区治理经验却在这片土地延续。

2014年2月，清华大学课题组与海淀区政府合作，在清河街道开启了基层社会治理创新试点，即新“清河实验”。

“快节奏的现代生活让邻里之间变得淡漠，社区居委会由于行政任务重，也难以发挥自治功能。”刘佳燕感慨。

1. Appropriateness for performing a previously omitted type of test

1. Appropriateness for .red[controlled comparison] with other cases

---

background-image: url("images/case_strategy.png")
background-position: center
background-size: contain

???

Gerring, John, and Lee Cojocaru. 2016. “Selecting Cases for Intensive Analysis: A Diversity of Goals and Methods.” Sociological Methods & Research 45(3): 392–423.

---

# Case Comparison

---

## Fundamental Logic of Case Comparison

* Most .red[similar] systems
* Most .red[different] systems

---

## Most Similar Systems (MSS, Concomitant Variation)

.bg-black.golden.ba.shadow-5.ph4.mt3[

The belief that systems as similar as possible with respect to as many features as possible constitute the optimal samples for comparative inquiry.

---

## Principles of MSS

**Focus**: .red[inter]systemic differences

**Assumption**: Characteristics shared by one group of systems, such as can be removed (control)

**Explanatory**: Difference

**Control**: Similarities between the systems

---

## Principles of MSS

**Focus**: .red[inter]systemic differences

**Assumption**: Characteristics shared by one group of systems, such as can be removed (control)

**Explanatory**: Difference

**Control**: Similarities between the systems
]

**Criteria**

- ~~Be objective~~
- ~~Be voiceless~~
- ~~Be replicated~~
- ~~Be generalized~~
- ~~.red[Be experimental]~~

]

???

Control, experiment?

---

## An Example of MSS

- **Objective**: Relationship between local bureaucrats and mass protest
- **Theory**: Consent instability vs. Mobilized instability
- **Findings**: 
    1. Mass protest can becomes a leverage for inter-bureaucratic bargaining;
    1. Superior' response depends on the escalation of protest and the appearance of violence
    1. Superior's response depends on whether the local bureaucrats' role in the protest and can effectively control the event
- **Method**: MSS

???
Deng, Yanhua, Zhenjie Yang, and Xiao Ma. 2021. “Riding on the Power of the Masses? How Different Modes of Mass Mobilization Shape Local Elite Bargaining in China.” *Journal of Chinese Governance*: 1–24.

Deng, School of Social and Behavioral Sciences, Nanjing University, Nanjing, China;

Yang, School of Humanities and Social Sciences, Macao Polytechnic Institute, Macao, China;

Ma, School of Government, Institute of Public Governance, Peking University, Beijing, China

---

- Prefecture-level city
- Mass protest
- Reason: Against turning the county to an urban district
- Result: 
    1. The county is still not a district
    1. Three incumbents were expelled from the party
    1. Two were stripped of positions
    1. Two retirees received serious within-party warnings

]

- Prefecture-level city
- Mass protest
- Reason: Against turning the county to an urban district
- Result: 
    1. The municipal government made a swift decision to halt the jurisdictional restructuring
    1. No county officials were publicly sanctioned afterwards.

]

.pull-left[
.red[    
- Differences:
    1. The protesters besieged the municipal government and violently damaged property within the compound.
    1. Directly involved in organizing the protest through organizations such as local business associations.
]
]

.pull-right[
.red[    
- Differences:
    1. Protest mobilizations remained largely peaceful throughout the end
    1. Relying on organizations such as a football-fan club
]
]

---

## Most Different Systems (MDS)

* **Focus**: .red[intra]systemic similarities and differences

* **Assumption**: systemic factors do not play any role in explaining the observed behavior.

* **Explanatory**: Similarity

* **Control**: Differences in the common systemic characteristics

---

## Comparison

<table class="table" style="margin-left: auto; margin-right: auto;">
 <thead>
  <tr>
   <th style="text-align:left;"> Item </th>
   <th style="text-align:left;"> MSS </th>
   <th style="text-align:left;"> MDS </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;font-weight: bold;border-right:1px solid;"> Assumption </td>
   <td style="text-align:left;border-right:1px solid;"> Similarity is irrelevant </td>
   <td style="text-align:left;border-right:1px solid;"> Differences is irrelevant </td>
  </tr>
  <tr>
   <td style="text-align:left;font-weight: bold;border-right:1px solid;"> Focus </td>
   <td style="text-align:left;border-right:1px solid;"> Difference </td>
   <td style="text-align:left;border-right:1px solid;"> Similarity </td>
  </tr>
  <tr>
   <td style="text-align:left;font-weight: bold;border-right:1px solid;"> Control </td>
   <td style="text-align:left;border-right:1px solid;"> Shared properties </td>
   <td style="text-align:left;border-right:1px solid;"> Different features </td>
  </tr>
  <tr>
   <td style="text-align:left;font-weight: bold;border-right:1px solid;"> Target </td>
   <td style="text-align:left;border-right:1px solid;"> Sufficiency </td>
   <td style="text-align:left;border-right:1px solid;"> Necessity </td>
  </tr>
</tbody>
</table>

---

# Mixed Method

---

## The "Perfect" Approach (Hmm...)

Terminology first:

> **Multimethodology** (or multimethod) research includes the use of more than one method of data collection or research in a research study or set of related studies.

> **Mixed methods** research is more specific in that it includes the mixing of .red[qualitative and quantitative] data, methods, methodologies, and/or paradigms in a research study or set of related studies.

---

## Types of Mixed Method

???

Johnson, R. Burke, Anthony J. Onwuegbuzie, and Lisa A. Turner. 2007. “Toward a Definition of Mixed Methods Research.” Journal of Mixed Methods Research 1(2): 112–33.

---

## Difficulties

**Data difference**   
Numbers vs. words

**Method difference**   
Probabilistic vs. deterministic

**Philosophical difference**    
Testing vs. understanding

---

## An Example of Mixed Method

- **Objective**: Vote buying
- **Theory**: (Rent seeking) Lure of rents &rarr; vote buying
- **Findings**: 
    1. Lure of rents &rarr; competitiveness 
    1. Lure of rents &rarr; proportion of vote buying
    1. Vote buying &rarr; recruitment of rent-sharing coalition
- **Method**: Mixed method (case + survey)
    1. In-depth case study (> 70 interviews)
    1. Panel surveys

???

Ma, Xiao, Susan H. Whiting, Tonglong Zhang, and Tan Zhao. 2022. “Vote Buying as Rent Seeking: Land Sales in China’s Village Elections.” *Studies in Comparative International Development*. https://doi.org/10.1007/s12116-022-09355-y (May 15, 2022).

School of Government and Institute of Public Governance, Peking University

Department of Political Science, University of Washington

College of Economics and Management, South China Agricultural University

Department of Public Administration, School of Public Administration and Policy, Renmin University of China

---

500-mu village land for sub-development

&darr;

Rents + compensation (5,000,000)

&darr;

Unprecedentedly competitive village election    
(Incumbent leader vs. Owner of a construction company)

&darr;

The owner bought votes through brokers and won the election

&darr;

The owner was then recruited by the local apparatus

&darr;

Hypothesis about vote buying &rarr;

]
]

???

A third candidate was a middle school teacher who reportedly borrowed money to buy votes, were quickly outbid and abandoned any attempt at vote buying.

- A multi-wave panel survey
    1. 2008: 2,000 households in 100 villages
    1. 2014: 1,240 households from a 60 village subsample
    
- Outcome variable: The overall vote-buying situation in the village’s most recent election
- Explanatory variable: Whether there was a land taking within one term of a village election
    - One term before or after the election
    - 3 yrs before
    - 3 yrs after

`$$VB_i = c + \beta land\_taking_i + XB + alpha_k + \epsilon_i$$`
- Result: land_taking significantly increased the probability of vote buying

]

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background-image: url("images/case_mindmap.png")
background-position: center
background-size: contain

## Take-Home Points

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background-image: url("images/cha_challenge.gif")
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