Issues, Media and Momentum in the 2008 Primary:
Automated Retrieval of Dynamic Content
Dino P. Christenson
Department of Political Science
R ESEARCH Q UESTIONS
IA NH
5
4
3
1
0
125
100
50
75
50
40
30
Jul
Sep
Oct
Nov
Dec
Jan
Feb
25
Traditional Republican Issue Dynamics
IA NH
NV SC
Super
0
Education
Poverty
Labor
Environment
Military
Economy
Spending
Taxes
Military
Economy
Morals
Spending
Taxes
Morals
Dynamic process
I Daily censoring at zero
I Sampling error from large daily sample sizes
I Large volatility in issue mentions
I Days of week and holiday media reporting
I FEC reporting deadlines
3
M OTIVATING K ALMAN F ILTER
4
5
Healthcare
0
L ARGER P ROJECT
Aug
1
I
Invisible
Early
Daily Issue Mentions (filtered)
I
Traditional Republican Issues
20
I
Traditional Democrat Issues
10
I
R AW I SSUES D ATA
Average Daily Issue Sentences
I
Explore issue salience in the 2008 presidential
primary campaign
Expose dynamic nature of the media’s issue
coverage as it pertains to both the invisible
primary period and the early primary
Generate smooth summary measures of the
dynamics with Bayesian state space models
Find that particular issues dominate the
campaigns at the start and finish, but that there
are also changes in the relative salience of issues
throughout the campaign
Showcasing data collection and potential use
Just the first few of several steps toward
understanding the dynamic relationship of
media issue coverage to indicators of candidate
status in the 2008 primary
0
I
Super
2
S UMMARY
NV SC
Education
Environment
Healthcare
Labor
Poverty
2
I
Traditional Democrat Issue Dynamics
How does media coverage of issues change over
the primary campaign?
To what extent is the coverage related to key
campaign events?
Daily Issue Mentions (filtered)
I
F ILTERED I SSUES
D ATA W ORD C LOUD
B AYESIAN S TATE S PACE M ODEL
Sample national and local newspapers
Test the dynamic mechanisms of primaries
Evaluate roles of media, polls, contributions and
candidate visits
Project with Corwin D. Smidt:
http://VisiblePrimary.com
Democratic Issues Dynamics
Super
IA NH
NV SC
Super
●
●
●
●
●
4
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
2
●
●
●
●
●
●
●
●●
●
●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
I
● ●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
3
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
I
●
●
●
●
●
●
●
●
●
●
●
●
3.5
●
1
●
●
●
●
●
3.0
●
0
Daily Issue Mentions (logged)
●
●
●●
●
●
●
●
●
●
●
●
● ●● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
I
●
●
●
●
I
Dec
Jan
Feb
●
Jul
Aug
I
●
Sep
Oct
Nov
Both horse-race & issue coverage increase over
the 2008 Primary
Defense dominates traditional Rep issues
Healthcare strongest among Dem issues
Economy important but not the leading concern
Moral values & spending with relatively little
attention
N EXT S TEPS
●
●
I
I
5
NV SC
●
●
I
Nov
Republican Issues Dynamics
IA NH
●
Counting number of sentences per day with a
salient issue in national newspapers
Timeline: July 9, 2007 to February 5, 2008
4,184 articles mentioning an issue
151,702 issue sentences
I
A GGREGATE F ILTERED S ERIES
D YNAMIC I SSUE C ONTENT
I
I
6.0
I
I
Bayesian State Space Model:
I Forward filtering backward sampling algorithm
I Inverse-Wishart priors for residuals
I Normal diffuse priors for regressors
5.5
I
I
θt = θt−1 + υt where υ˜N(0, σ2υ )
5.0
I
Oct
Transition equation:
4.5
I
Sep
C ONCLUSION
Issuest = θt + Dayt + FECt + ϵt where ϵ˜N(0, σ2t )
4.0
I
Aug
State equation:
Original longitudinal
dataset culled from
newspaper articles
Use Perl to
automatically
retrieve and code
articles
Daily Issue Mentions (logged)
I
Jul
Dec
Jan
Feb
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
I
Web: http://www.polisci.osu.edu/grads/dchristenson/
Further filter the series by taking into account
candidate visits & other cycles
Extend timeline to include period leading up to
conventions
Explicit hypothesis tests of role of issue coverage
(dynamic ownership & status)
Address theories of bottom-up vs top-down
issue salience in campaigns
Multivariate perspectives: BVAR
Email: christenson.24@polisci.osu.edu