Generating Data on Comparative Salaries
Average Salaries per country/engineering field/experience level
The data for the average salaries of engineers from SA, UK, US and Australia in the fields of mechanical, chemical, electrical and civil was found on Payscale.com, a website that aggregates the employment information of thousands of users, including engineers, across different levels of experience ranging from those new to the industry to the veterans with more than 20 years experience.
Salaries after tax
The average salaries from each country, for each field, and within four ranges of experience (0-5 year, 5-10 years, 10-20 years and >20) were then each run through the online tax calculators of each respective country (with the most basic settings) to get salaries per year after tax.
Applying Purchasing Power Parity (PPP)
The amounts generated by the above processes only served to illustrate the nominal value of earnings in each country’s local currency, but to be able to compare all the values they need to be translated into a single currency. Rather than using the current nominal exchange rate, the theory of Purchasing Power Parity – an economic theory that estimates the amount of adjustment needed on the exchange rate between countries in order for the exchange to be equivalent to each currency’s purchasing power – was applied to find a ‘real exchange rate’ (for instance R5 can get you the equivalent of $1 of the same goods, which suggests a much lower exchange rate than the current R15/$1 rate) between the respective countries and all the foreign values were subsequently converted to rands. The World Bank’s PPP adjustment were used.