Top-coding of Income Variables
Because extremely high incomes are rare, releasing this information can increase the risk of disclosure. Therefore to ensure that people with a very high income are not identifiable in any way, reported income beyond a certain amount is top-coded to a maximum annual value of £180,000. Note that some of the income variables could be reported on rates other than an annual basis. When these variables were reported for different rates, the values were top-coded to be equivalent to that of the annual maximum value at the reported rates. For example, an annual maximum value of £180,000 would lead to top-coded values of £15,000 for reports on a monthly basis. The variables affected by this top-coding and the maximum annual values are reported in the table below.
Top-coded variables and maximum value
| Variable | Description | Top-coded value |
|---|---|---|
| w_fiyrdia | Amount received in interest/dividends | 180,000 |
| w_fiyrdic_dv | Income from savings and investments (annual) | 180,000 |
| w_j2pay | Gross earnings from seconds jobs last month | 15,000 |
| w_paygu_dv | Usual gross pay per month: current job | 15,000 |
| w_paynu_dv | Usual net pay per month: current job | 15,000 |
| w_payu_dv | Usual pay per month | 15,000 |
| w_payu | Usual pay | 180,000 |
| w_payg_dv | Gross pay per month in current job: last payment | 15,000 |
| w_payn_dv | Net pay per month in current job: last payment | 15,000 |
| w_jsprf | Self-employed: net profit in last yearly account | 180,000 |
| w_jspayu | Average income from job/business | 15,000 |
| w_seearngrs_dv | Self-employment earnings – gross | 15,000 |
| w_fimnlabgrs_dv | Total monthly labour income – gross | 15,000 |
| w_fimngrs_dv | Total personal income – gross | 15,000 |
| w_paygl | Gross pay at last payment | 180,000 |
| w_paynl | Net pay at last payment | 180,000 |
