The profession of Technical Author in the UK is yet to be recognised as a distinct profession under the UK Standard Industrial Classification of Economic Activities, so it’s very hard to determine how many people work as Technical Authors.
One way of estimating the number of Technical Authors may be by looking at statistics from the USA. The US Bureau of Labor Statistics’ Occupational Outlook Handbook now includes details on technical writers, and it estimates there are 48,900 technical writers employed in the USA.
According to the World Bank, the UK economy is 18.66% the size of the USA ($2.13 Trillion, compared to $14.2 Trillion). So, if we assume the UK and USA economies are comparable, then we can estimate there are (48,900 x 18.66%) 9,100 Technical Authors in the UK.
The Australian Bureau of Statistics also recognises Technical Authors as a profession (the classification is 212415 “Technical Writer”), and estimates there are 2,115 employed in Australia (Source: Table 1 – ASCO Second Edition to ANZSCO First Edition – Australia). By using the GDP calculation again ($1.02 Trillion, compared to $2.13 Trillion), our estimate becomes 4,416 UK Technical Authors.
So perhaps we can estimate the number being between 4,500 and 9,000.