thirty-thousand.org
 
return to home page
 


Correlation Analysis of House Representatives’
Reelection Rates vs. Historical House District Sizes
 

 
This analysis evaluates the history of reelected incumbents as a percentage of the total House delegation and how those rates correlate to the average House district sizes historically. The purpose of this analysis is to illustrate:

  • the reelection trend in the U. S. House of Representatives; and,
  • how that trend correlates to House district sizes historically.

During the early 1800s, the average House district size remained below 50,000 (as was intended by the Founding Fathers). Today, the average House district size is over 660,000. As House district sizes grow larger, so does the amount of funding required for a non-incumbent candidate to unseat an incumbent Representative. Consequently, it is easy to understand why reelection rates currently are hovering around 90%.
 
This analysis focuses on the number of House seats occupied by Representatives who are reelected from the prior term. The time period is from the first through the 108th congresses. See Notes below for additional information regarding the analysis.
 

Also see Historical Population and U. S. House District Data
for additional data related to the chart above.

 
The top (blue) graph in the chart above indicates the percentage of House Representatives which were reelected from the previous term (plotted against the right Y-axis). The lower (red) graph is the average size of House districts nationwide (plotted against the left Y-axis).
 
For each of the graphs, the dashed line graphically illustrate their respective underlying trends as determined by a least squares regression.
 

The coefficient of correlation between these two graphs is indicated in the table inset in the chart above. For the 108 congresses plotted, the correlation factor is .79. Also shown is the correlation since 1913 (when the size of the House was increased to 435). This correlation factor is .62.
 
The number of data pairs that comprise each correlation analysis is also provided (“n”). This n value is actually the size of the population; not a sampling.
 
These correlation factors are also calculated for each state (see table below). However, due to the states’ smaller n values, the correlations become less evident.
 

Historical
House District Data for
each State
 

Since Admission

Since 1913

 

Year

Congress

Correl.

n=

Year

Congress

Correl.

n=

US

1789

1st

0.79

10,492

1913

63rd

0.62

2,697

AL

1819

16th

0.43

179

1913

63rd

-0.11

72

AK

1959

86th

0.47

4

       

AZ

1913

63rd

0.00

29

1913

63rd

0.00

29

AR

1835

24th

0.28

92

1913

63rd

-0.15

51

CA

1851

31st

0.76

334

1913

63rd

0.53

141

CO

1875

44th

0.13

61

1913

63rd

0.02

48

CT

1789

1st

0.28

214

1913

63rd

0.49

74

DE

1789

1st

0.20

61

1913

63rd

0.49

21

FL

1845

29th

0.31

106

1913

63rd

0.36

87

GA

1789

1st

0.43

954

1913

63rd

-0.07

62

HI

1963

88th

0.29

9

       

ID

1889

51st

0.17

30

1913

63rd

-0.01

25

IL

1817

15th

0.54

450

1913

63rd

0.62

96

IN

1815

14th

0.53

309

1913

63rd

0.23

74

IA

1847

30th

0.38

179

1913

63rd

0.04

79

KS

1861

37th

0.21

113

1913

63rd

0.02

64

KY

1791

2nd

0.54

338

1913

63rd

0.20

43

LA

1811

12th

0.40

154

1913

63rd

0.19

67

ME

1821

17th

0.17

155

1913

63rd

-0.11

38

MD

1789

1st

0.56

278

1913

63rd

0.17

58

MA

1789

1st

0.57

413

1913

63rd

0.21

43

MI

1837

25th

0.61

260

1913

63rd

0.39

103

MN

1857

35th

0.43

128

1913

63rd

0.34

87

MS

1817

15th

0.44

123

1913

63rd

0.04

46

MO

1821

17th

0.58

298

1913

63rd

0.44

76

MT

1889

51st

0.14

32

1913

63rd

0.02

25

NE

1867

40th

0.17

91

1913

63rd

0.22

57

NV

1863

38th

0.22

31

1913

63rd

0.18

19

NH

1789

1st

0.30

143

1913

63rd

-0.01

27

NJ

1789

1st

0.63

309

1913

63rd

0.48

72

NM

1913

63rd

0.32

26

1913

63rd

0.32

25

NY

1789

1st

0.85

1,420

1913

63rd

0.56

47

NC

1789

1st

0.52

321

1913

63rd

-0.10

64

ND

1889

51st

0.23

27

1913

63rd

0.17

21

OH

1803

8th

0.63

635

1913

63rd

0.60

63

OK

1907

60th

0.40

78

1913

63rd

0.40

76

OR

1859

36th

0.54

60

1913

63rd

0.02

39

PA

1789

1st

0.72

1,012

1913

63rd

0.59

60

RI

1789

1st

0.29

72

1913

63rd

0.15

23

SC

1789

1st

0.38

213

1913

63rd

-0.11

50

SD

1889

51st

0.08

35

1913

63rd

-0.07

25

TN

1795

4th

0.57

260

1913

63rd

0.13

61

TX

1845

29th

0.46

238

1913

63rd

0.11

128

UT

1895

54th

0.00

37

1913

63rd

-0.09

33

VT

1791

2nd

0.27

95

1913

63rd

0.08

15

VA

1789

1st

0.48

404

1913

63rd

0.04

44

WA

1889

51st

0.28

75

1913

63rd

0.17

65

WV

1863

38th

0.49

98

1913

63rd

0.42

58

WI

1847

30th

0.52

176

1913

63rd

0.40

89

WY

1889

51st

0.17

17

1913

63rd

0.14

14

 
Across the states, there is a clear correlation between n and the the coefficient of correlation. That is, across the states, the larger the population size, n, the larger the coefficient of correlation. In fact, the correlation between the states’ respective n values and correlation factors is 0.675 (n = 50).

Notes:

The analysis focused only on consecutive terms served by the same congressperson, i.e., in succession without interruption. The numerator for this analysis is the number of Representatives who also served in the preceding term. The numerator includes elected (and reelected) Representatives even if they subsequently did not serve their term for any reason (e.g., death).
 
The denominator was the number of seats authorized by Congress (for each state) regardless of how many Representatives actually served during that Congress. The number who actually serve was often larger than the number authorized due to turnover (e.g., death or resignation). In a few cases the number who served was fewer than what was authorized (most particularly for those states who temporarily secede to the Confederacy during the 1860s).
 
The results of this analysis would approximate, but would not be identical to, the percentage of incumbents who seek reelection and win. The latter percentage would be higher in those instances where some incumbents choose not to stand for reelection.
 
Not reflected in this analysis is the advantage that can be bestowed on an incumbent’s family member (e.g., wife or son) running for that incumbent’s vacant seat.
 
The source of the data for this analysis was the “Biographical Directory of the United States Congress” [link]. In a number of cases, corrections were made to the table data generated by this resource to be consistent with the biographical descriptions provided by this same resource.


“If a nation expects to be ignorant and free ... 
     it expects what never was and never will be.”

– Thomas Jefferson
Created: 15DEC2004
Last updated:15DEC2004
© 2004 thirty-thousand.org

Web Pamphlet