Upper South Island maps

Data source Data is sourced from Inland Revenue GST sales information. The mapped data is based on GST sales for monthly filers and 'TA' two-monthly GST filers with two exclusions" businesses with more than one geographical location in the upper South Island businesses that are part of a complex GST group. Calculating GST aggregates Using the monthly and ‘TA’ GST returns, we summed GST exclusive sales values for the following balance dates, so each balance date covers a two-month period: November 2015 January 2016 March 2016 November 2016 January 2017 March 2017. Mapping methodology We made the maps by first geocoding businesses to their location on the ground. Then, the businesses were ‘binned’ into a hexagonal grid, where we added the difference values of all businesses together. Lastly, we calculated the centroid (geographic centre of a polygon). This formed the data point, which we then symbolised using a cartographic technique called ‘firefly mapping’, to produce the maps seen with the release. As such, each dot on a map represents a collection of businesses. Dollar-change map dots The markers on the map show the size and direction of sales movements from the same period of the previous year, for a given geographic area. Size of change Criteria Large increase >$300,000 sales increase Small increase $30,000 to $300,000 sales increase Little change <$30,000 sales change Small decrease $30,000 to $300,000 sales decrease Large decrease >$300,000 sales decrease We used annual movements to remove most of the seasonal effect on the data. However, as Easter fell in March in 2016 and April in 2017, decreases are evident in tourist destinations such as the Marlborough Sounds, Motueka, and parts of the West Coast on the February–March map. Confidentiality Areas represented by fewer than three businesses were merged with neighbouring areas. Where there were insufficient businesses to merge together, we suppressed the data. Data Quality The GST data includes sales of goods and services and other income such as sales of capital items and businesses, and potentially insurance payouts resulting from the earthquakes ( see insurance and depreciation). Some large capital items that could be identified at an aggregate level were removed from the series. en-NZ