Look Who’s Talking: Bipartite Networks as Representations of a Topic Model of Parliamentary Speeches

Ben Curran, Kyle Higham, Elisenda Ortiz, Demival Vasques Filho

COMPASS seminar, October 16, 2017

1/16 Outline

1 Introduction Motivation Background

2 Methods & data Dataset Topic modeling Bipartite networks

3 Results Verbosity Topics evolution Network analysis

4 Conclusions

2/16 Motivation

• Lack of quantitative methods to measure the participation to parliamentary debate and discourse of elected Members of Parliament (MPs).

• To develop an exploratory study for a quantitative analysis of politics, using parliamentary speeches and based on topic modeling and network analysis.

3/16 Background

• Two-party era for most of the 20th century: National (right-leaning) and Labour (left-leaning).

• Adoption of mixed-member proportional (MMP) system in 1996: smaller parties join.

• Smaller parties balancing the power.

• Four terms were analyzed: 2002-2005, 2005-2008, 2008-2011, 2011-2014.

• Government transition in period analyzed: Labour (2002-2008) and National (2008-).

4/16 Dataset • New Zealand Hansard database - speeches, • more than 150 words long, • about 48,000 speeches. • nearly 40 million words

000 0

000

000

0 0 00 000 00 000

5/16 Topic modeling

L L L

6/16 Bipartite networks

Jeanette Fitzsimons David Parker

John Key

Amy Adams

John Key David Parker Jeanette Fitzsimons

Louise Upston

7/16 Verbosity

4 4 4

8/16 Topics evolution

All parties National All parties National 0.072 0.072 0.072 0.072

0.048 0.048 0.048 0.048

0.024 0.024

Topic proportion 0.024 0.024 Topic proportion

0 0 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 Year Year Year Year

Foreign affairs Justice Economy Development Environment Housing Canterbury Transport

Labour Greens Labour Greens 0.072 0.072 0.072 0.12

0.048 0.08 0.048 0.048

0.024 0.04 0.024 0.024 Topic proportion Topic proportion

0 0 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 2004 2007 2010 2013 2016 Year Year Year Year

9/16 Networks

47th 48th

75 158 113 17 28 85 52 197 130 198 199 17 218 118 61 152 82 76 10355 49 121 108 32 229 156 50 185 26 42 33 88211 53 221 84 90 104 81 216 125 224 227 54 195 38 99 132 10 92 53 171 107 209 137 167 154 105 230 230 115 203 204 117 96 163201 95 118 31 57 215 15 12 66 148 134 139 87 171 21 101 147 28 209 40 176 225 182 130 210154 155 82 180 138 187 106 195 188 25 153 62 47 43 161 156 202 62 210 128 10 166 190 43229 16312 181 213 158 88 85 79 5 122 52 2 42 198 11 139 75 204 119 87 45 95 203 211 92 3 70 191 90 166 177 79 128101 202 179 93 45 197 109 187 23 151 207 206 189 201 104 119 22 155 124 663 221 140 24 32 225 68 84 228 47 39 23 168 205 5 8 22 31 216 40 71 106 127 99 98 173 74 206 93 125 162 180 121 190 48105 226 175 20 74 157 189 29 113 123 193 81 15 Mana 153 138 146 143 109 55 33 199 185 108 123 152 159 Labour 200 122 188 39 29 98 Progressive Greens ACT Maori 49th National 50th 48 80 98 8 50 33 1 227 199 First 184 50 186 94 123 229 36 208 126 189 138 176 198 172 88 63 66 211 175 67 6 153 85223 120193 123 57 23 162 13 30 51 210 174 200 165 40200 118 74 148150 37 185 39 162 19 41 196 102 192 16 27 206 226 133179 59 14 14826 9 212 107 36 5 83 214 195 121 216 73 166110 81 91 141 157 131 93 76 184 219 114 76 173 21 38 60 194 144 39 219 197 222 115 18 151 73 15831 29 126 224 64 40 60 91 143 97 209 156 178 211 1974 43 57 77 183 86 105 173 66 58 160 101 86 21 56 210 105 150 198 226 102 213 32 224 72 175 141 151 111107 134 116 64 174 185 225 89 130 85 157 26 44 46 136 129 201225 134 214 115 17 13 25 79 7 89190 38 63 59 118 132 88 79 217 165 183 34 164 142 206 58 110 78 28 92 172 133 6 33 178 179 10 23 170156 42 10 193 145 131 169 41 25 176 16 72 202 153 43 166 213 20 109 116 132 209 56 97 48 186 112 8 180 138 227 190 135 65 145 5213620315 197 35 121 10/16 Degree distributions

0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0

0 0 0 0 0

0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

11/16 MPs and average degree

Term National Labour Greens others 47th 26 52 8 19 48th 48 50 7 16 49th 58 47 11 11 50th 61 39 14 11

4 4 4

12/16 Party homophily

4 4 4

13/16 Communities

4

4 4 4

14/16 Conclusions

• More verbosity since 2008, coinciding with financial crisis and change in government. • Opposition party tends to be more verbose in parliament. • Topic trends: housing (from 2013), Canterbury (from 2011), economy (from 2008). • Topic preferences: environment (Green) and economy (National). • More heterogeneity of topics of interest over time. • Increasing homophily (MPs sharing more interests within their parties). • Formation of big National community - party cohesion once in government, different behavior than when Labour was in government. • Influence of small parties are reducing over time.

15/16 Thank you! Questions?

16/16