Fig 1.
Distribution of word-counts for New Zealand parliamentary speech.
Speeches delivered in the period February 2003 to August 2016. In blue, the speech sizes used in our analysis. Speeches shorter than 150 words are omitted from our analysis due to lack of topical content, this threshold is indicated by the dashed vertical line.
Fig 2.
Topics identified by an LDA-based topic model of the Hansard speech corpus.
Topics for the period February 2003 to August 2016 and their respective normalized proportions as a fraction of all the topical content discovered after the omission of nine topics with little specific thematic content. A list of topics and the keywords that comprise them can be found in S2 Table.
Fig 3.
Schematic drawing of a bipartite network and its projections.
(a) Bipartite network and its projections onto set of nodes (b) U, where nodes represent MPs, and (c) V, where nodes represent topics. In (b) and (c) the numbers on top of the links indicate the weights, which correspond to the number of common neighbors that two linked nodes share in the bipartite network.
Fig 4.
Total number of words spoken by each party.
Number of words in their speeches longer than 150 words, for each of the four complete parliamentary terms studied.
Fig 5.
Evolution of topic proportions 1.
Evolution over time of the proportions in which the topics labeled as Foreign Affairs, Law and order, Economy, and Growth, are discussed at the Parliament, and the corresponding decomposition by party. Grey dotted lines indicate the change of government from Labour to National in 2008.
Fig 6.
Evolution of topic proportions 2.
Evolution over time of the proportions in which the topics labeled as Environment, Housing, Canterbury, and Transport, are discussed at the Parliament, and the corresponding decomposition by party. Grey dotted lines indicate the change of government from Labour to National in 2008. Note the change in scale in the Topic proportion axis for the Green Party time series to accommodate their notable interest in environmental policy.
Fig 7.
MP networks for parliaments 47th to 50th.
Networks corresponding to the MP-projection of the original bipartite network. Node size is proportional to the total number of words spoken by each MP over the course of the parliamentary term. Node labels identifying MPs are provided in S1 Table.
Table 1.
Number of members of parliament in the three largest parties (as of the 50th parliament) for each complete parliamentary term studied.
Fig 8.
Size and party composition of the three largest communities.
Network communities discovered in the MP-projected network for each of the parliaments examined.
Fig 9.
(a) Number of MPs linked to each topic in the original bipartite network, (b) number of topics linked to each MP in the original bipartite network, and (c) number of links each MP has to other MPs in the MP-projected network.
Fig 10.
(a) Time series of the average degree of MPs in the MP-projected network, decomposed by party. (b) Time series of net homophily in the MP-projected networks for the empirical data and configuration model. The results show average and standard deviation over 1000 runs.