Peter's stats stuff

Applying statistics and data science 'in the wild'

I write about applications of data and analytical techniques like statistical modelling and simulation to real-world situations. I show how to access and use data, and provide examples of analytical products and the code that produced them.

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Recent posts

New Zealand fatal traffic crashes

15 October 2017

I explore half a million rows of disaggregated crash data for New Zealand, and along the way illustrate geo-spatial projections, maps, forecasting with ensembles of methods, a state space model for change over time, and a generalized linear model for understanding interactions in a three-way cross tab.

New Zealand 2017 election results

07 October 2017

New Zealand's election results have been released and were within the range of my probabilistic predictions. The pollsters did a good job.

nzelect 0.4.0 on CRAN with results from 2002 to 2014 and polls up to September 2017

05 October 2017

A new version of the nzelect R package is on CRAN, with election results by voting location back to 2002, and polls up to the latest election. I show how to extract and understand the "special" votes and how they are different to advance voting.

Time-varying house effects in New Zealand political polls

16 September 2017

I adjust my state-space model of New Zealand voting behaviour to allow for the house effect of one of the pollsters to change from the time they started including an on-line sample, and get some interesting results.

R Markdown for documents with logos, watermarks, and corporate styles

09 September 2017

I outline how I structure analytical project folder systems and some hints for matching R Markdown documents to a corporate style guide including adding logos, watermarks, and of course colours and fonts.

The long view on New Zealand political polls

09 September 2017

New Zealand electoral polls going back 15 years

More things with the New Zealand Election Study

20 August 2017

I introduce a new web app that allows nons-specialists to explore voting behaviour in the New Zealand Election Study, and reflect on what I've done so far with that data.

Estimating Gini coefficient when we only have mean income by decile

19 August 2017

Calculating the Gini coefficient for inequality directly of mean income by decile produces a slightly biased downwards estimate. I correct for this and demonstrate on the World Panel Income Distribution data.

Sampling distribution of weighted Gini coefficient

05 August 2017

I play around with the sampling distribution of Gini coefficients calculated with weighted data; and verify that the Gini calculation method in a recent Stats NZ working paper is the one in the acid R package.

Inter-country inequality and the World Development Indicators

22 July 2017

I play around with population-weighted income inequality of countries with data from the World Development Indicators, re-creating (with some amendments) some graphics from Branko Milanovic's recent book "Global Inequality".