As part of the Core survey, GWI asks all respondents about their annual household
In each country, we use the results from the household income question to determine income segments – dividing people into the Lower Quartile/Bottom 25%, the Middle Quartile/Mid 50% or the Upper Quartile/Top 25%. We also break out the Top 10% (who still appear within the Top 25% too).
These segments exclude anyone who answered “Don’t know” or “Prefer not to say” in the income question; these individuals are instead included in the “Prefer not to say” segment. To allow a way to analyze these respondents alongside those who did give an income answer, we have developed a separate social grading classification which factors in much more in addition to income. You can find details of this here.
To assign respondents to an income quartile, we look at the spread of responses received in that country in that quarter’s wave of research. There are three key things to note about this:
- Respondents are assigned to a segment based on how their answer compares to everyone else we surveyed in their country only, and not against any respondents in any other markets.
- Because average incomes can differ so much between countries, that means the thresholds of each segment are likely to be different from one country to the next; in a market like the US where average incomes are among the highest globally, the incomes of those in the top 25% are likely to be considerably greater than those in markets with low average incomes (e.g. African markets like Kenya and Nigeria). This has an impact on how the data should be interpreted when analyzed at a global level. Rather than showing the top 25% of global respondents – which would cause a huge skew towards wealthy markets – it displays aggregated data for the top 25% from each country.
- As the segments are created after each wave of research and are based on the answers captured that quarter, the thresholds for each segment might be subject to wave-on-wave variation. In the US, for example, it might be that those with an income of less than 25,000 comprise the bottom 25% in one wave, whereas in the subsequent wave it comprises those with an income of less than 32,000. In practice, it tends to be the same brackets that contribute to the same segments each quarter, but you can double check this by applying the income segments as audiences on the annual household income question.
As a result of asking people to select an income bracket rather than entering an exact amount, it is not currently possible to give a precise value for the threshold of each income segment. However, we can determine the income brackets that normally contribute to each segment by looking at the Q1-Q2 2017 data.
You can find the brackets per market in the below document: