In our July survey we asked people to say at which point they thought wealth began. What sort of income (calculated per capita for each family member) would allow someone to be called really rich?

Respondents most often chose an amount somewhere between 5000 and 14,999 PLN net per capita per month (46% of all responses fell into this range). The most frequent answer (the mode) was 10,000 PLN net per month. The median value (the midpoint in the list of amounts chosen) was an identical 10,000 PLN.

With this kind of variable, the median is a better measure than the mean, which is more susceptible to being affected by a small number of answers where extremely high values have been chosen. This effect can be partly corrected by excluding outlying responses. After applying this procedure, with amounts below 2000 PLN and over 100,000 PLN deemed to be outliers, the mean came to 16,305 PLN.

More on this subject in the CBOS report.