| Implied MP at 2017: | Stephen Doughty (LAB) |
| County/Area: | South Glamorgan (Wales) |
| Electorate: | 90,232 |
| Turnout: | 68.0% |
| Party | Implied 2017 Votes | Implied 2017 Share |
|---|---|---|
| LAB | 38,935 | 63.5% |
| CON | 14,229 | 23.2% |
| LIB | 4,760 | 7.8% |
| Plaid | 1,906 | 3.1% |
| UKIP | 805 | 1.3% |
| Green | 620 | 1.0% |
| OTH | 59 | 0.1% |
| LAB Majority | 24,706 | 40.3% |
See overview of other seats in Wales.
This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Cardiff South and East been in force at that time. The basic idea of the calculation is to look at the district council wards which make up the new seat, and estimate how they voted in 2017. This estimate is based on the recent local election results in those wards, with adjustments made to allow for different turnouts and different voting patterns for local and general elections.
In many cases, wards are divided between several old constituencies or between new constituencies. So the same ward may be shown more than once, but the electorate shown will reflect that ward sub-section.
Election results from a recent local election are given. This is usually the local election closest to 2015 from the period 2012-2015. For multiple-member wards, the votes shown are the sum of the votes cast for all candidates of each party. A negative number indicates candidate(s) elected unopposed.
There are two problems with using the raw (actual) local election results to imply general election results ward-by-ward. Firstly, turnout can be different between local and general elections, which means that the total number of local votes cast does not equal the number of votes cast in each old seat at the general election. To correct for this, we adjust the local votes to match the general election turnout. Each ward's result is scaled, whilst keeping constant the percentage support for each party, so that the total turnout adds up to the old seat's general election turnout. All wards in the old seat are assumed to have the same percentage turnout.
Secondly, even though we now have the correct number of votes in the old seat, the party totals will not match the general election result. Some parties do better at the local election than the general election, and others do vice versa. We call these strong and weak parties respectively. The next step is to transfer votes from strong parties to weak parties. This is done by taking votes proportionally away from strong parties and putting them in a transfer pool. For instance if a party got 12,500 local votes, but only 10,000 general election votes, it will lose 20% over all the wards. These votes in each ward will be put in the ward's transfer pool and allocated to the weak parties. Weak parties will get votes transferred to them in proportion to the votes they need over the old seat. For instance, if two weak parties need 4,000 and 1,000 votes respectively, the first party will get 80% of each ward's transfer pool and the second party will get 20% of each ward's transfer pool. The transfer of votes between parties is done using the Electoral Calculus Transition Model.
More details of the calculation formulas are available.
The old seat(s) needed are:
The table shows the transfer-adjusted results for each ward in the old seat of Cardiff Central, as well as showing which new seat each ward is in.
| Old seat: Cardiff Central | Transfer-adjusted Results | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| District | Ward | Electorate 2017 | New Seat | CON Votes | LAB Votes | LIB Votes | UKIP Votes | Green Votes | Plaid Votes | MIN Votes | OTH Votes | Total Votes |
| Cardiff | Adamsdown | 5,044 | Cardiff South and East | 570 | 3,327 | 630 | 43 | 54 | 122 | 0 | 0 | 4,746 |
| Cardiff | Cathays | 7,176 | Cardiff South and East | 1,866 | 5,825 | 1,196 | 64 | 122 | 155 | 0 | 0 | 9,228 |
| Cardiff | Cyncoed | 8,139 | Cardiff North | 1,801 | 2,483 | 612 | 35 | 35 | 147 | 0 | 0 | 5,113 |
| Cardiff | Pentwyn | 10,435 | Cardiff North | 1,111 | 4,744 | 1,044 | 92 | 37 | 142 | 0 | 0 | 7,170 |
| Cardiff | Penylan | 9,188 | Cardiff South and East | 1,365 | 3,314 | 820 | 49 | 57 | 190 | 0 | 0 | 5,795 |
| Cardiff | Plasnewydd | 9,421 | Cardiff South and East | 1,284 | 5,500 | 1,113 | 60 | 115 | 242 | 0 | 0 | 8,314 |
| Total | 49,403 | 7,997 | 25,193 | 5,415 | 343 | 420 | 998 | 0 | 0 | 40,366 | ||
The full details of these calculations are given on the Cardiff Central seat details page. Click on "Show workings".
The table shows the transfer-adjusted results for each ward in the old seat of Cardiff North, as well as showing which new seat each ward is in.
| Old seat: Cardiff North | Transfer-adjusted Results | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| District | Ward | Electorate 2017 | New Seat | CON Votes | LAB Votes | LIB Votes | UKIP Votes | Green Votes | Plaid Votes | MIN Votes | OTH Votes | Total Votes |
| Cardiff | Gabalfa | 4,045 | Cardiff South and East | 1,827 | 2,857 | 232 | 59 | 0 | 217 | 0 | 0 | 5,192 |
| Cardiff | Heath | 9,326 | Cardiff North | 3,357 | 3,537 | 287 | 67 | 0 | 226 | 0 | 0 | 7,474 |
| Cardiff | Lisvane | 2,871 | Cardiff North | 1,382 | 632 | 38 | 12 | 0 | 39 | 0 | 0 | 2,103 |
| Cardiff | Llandaff North | 5,722 | Cardiff North | 1,343 | 2,992 | 201 | 50 | 0 | 98 | 0 | 0 | 4,684 |
| Cardiff | Llanishen | 12,916 | Cardiff North | 4,340 | 5,147 | 306 | 186 | 0 | 379 | 0 | 0 | 10,358 |
| Cardiff | Pontprennau / Old St Mellons | 6,976 | Cardiff North | 2,496 | 2,868 | 120 | 42 | 0 | 186 | 0 | 0 | 5,712 |
| Cardiff | Rhiwbina | 9,129 | Cardiff North | 3,127 | 3,212 | 182 | 73 | 0 | 119 | 0 | 0 | 6,713 |
| Cardiff | Whitchurch and Tongwynlais | 12,673 | Cardiff North | 4,037 | 4,837 | 348 | 93 | 0 | 473 | 0 | 0 | 9,788 |
| Total | 63,658 | 21,909 | 26,082 | 1,714 | 582 | 0 | 1,737 | 0 | 0 | 52,024 | ||
The full details of these calculations are given on the Cardiff North seat details page. Click on "Show workings".
The table shows the transfer-adjusted results for each ward in the old seat of Cardiff South and Penarth, as well as showing which new seat each ward is in.
| Old seat: Cardiff South and Penarth | Transfer-adjusted Results | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| District | Ward | Electorate 2017 | New Seat | CON Votes | LAB Votes | LIB Votes | UKIP Votes | Green Votes | Plaid Votes | MIN Votes | OTH Votes | Total Votes |
| Cardiff | Butetown | 6,524 | Cardiff South and East | 1,396 | 2,633 | 181 | 122 | 81 | 362 | 0 | 8 | 4,783 |
| Cardiff | Grangetown | 11,671 | Cardiff West | 2,365 | 5,515 | 322 | 136 | 138 | 622 | 0 | 51 | 9,149 |
| Cardiff | Llanrumney | 7,387 | Cardiff South and East | 1,150 | 3,673 | 102 | 94 | 33 | 167 | 0 | 5 | 5,224 |
| Cardiff | Pontprennau / Old St Mellons | 117 | Cardiff North | 34 | 38 | 2 | 1 | 1 | 2 | 0 | 0 | 78 |
| Cardiff | Rumney | 6,304 | Cardiff South and East | 1,387 | 2,483 | 66 | 74 | 26 | 85 | 0 | 15 | 4,136 |
| Cardiff | Splott | 8,454 | Cardiff South and East | 1,413 | 4,267 | 204 | 107 | 56 | 193 | 0 | 25 | 6,265 |
| Cardiff | Trowbridge | 10,585 | Cardiff South and East | 1,971 | 5,056 | 216 | 133 | 76 | 173 | 0 | 6 | 7,631 |
| Vale of Glamorgan | Cornerswell | 3,885 | Vale of Glamorgan East | 844 | 1,402 | 72 | 44 | 19 | 108 | 0 | 5 | 2,494 |
| Vale of Glamorgan | Llandough | 1,454 | Vale of Glamorgan East | 339 | 509 | 15 | 16 | 6 | 43 | 0 | 4 | 932 |
| Vale of Glamorgan | Plymouth | 4,419 | Vale of Glamorgan East | 1,502 | 1,011 | 81 | 40 | 18 | 98 | 0 | 14 | 2,764 |
| Vale of Glamorgan | St Augustine's | 4,913 | Vale of Glamorgan East | 1,244 | 1,467 | 89 | 44 | 52 | 170 | 0 | 16 | 3,082 |
| Vale of Glamorgan | Stanwell | 3,178 | Vale of Glamorgan East | 696 | 1,231 | 47 | 29 | 14 | 77 | 0 | 5 | 2,099 |
| Vale of Glamorgan | Sully | 3,531 | Vale of Glamorgan East | 979 | 898 | 33 | 101 | 12 | 61 | 0 | 16 | 2,100 |
| Total | 72,422 | 15,320 | 30,183 | 1,430 | 941 | 532 | 2,161 | 0 | 170 | 50,737 | ||
The full details of these calculations are given on the Cardiff South and Penarth seat details page. Click on "Show workings".
| New seat: Cardiff South and East | ||||||||||||
| District | Ward | Electorate 2017 | Old Seat | CON Votes | LAB Votes | LIB Votes | UKIP Votes | Green Votes | Plaid Votes | MIN Votes | OTH Votes | Total Votes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cardiff | Adamsdown | 6,971 | Cardiff Central | 570 | 3,327 | 630 | 43 | 54 | 122 | 0 | 0 | 4,746 |
| Cardiff | Butetown | 7,213 | Cardiff South and Penarth | 1,396 | 2,633 | 181 | 122 | 81 | 362 | 0 | 8 | 4,783 |
| Cardiff | Cathays | 13,554 | Cardiff Central | 1,866 | 5,825 | 1,196 | 64 | 122 | 155 | 0 | 0 | 9,228 |
| Cardiff | Gabalfa | 6,708 | Cardiff North | 1,827 | 2,857 | 232 | 59 | 0 | 217 | 0 | 0 | 5,192 |
| Cardiff | Llanrumney | 7,879 | Cardiff South and Penarth | 1,150 | 3,673 | 102 | 94 | 33 | 167 | 0 | 5 | 5,224 |
| Cardiff | Penylan | 8,510 | Cardiff Central | 1,365 | 3,314 | 820 | 49 | 57 | 190 | 0 | 0 | 5,795 |
| Cardiff | Plasnewydd | 12,211 | Cardiff Central | 1,284 | 5,500 | 1,113 | 60 | 115 | 242 | 0 | 0 | 8,314 |
| Cardiff | Rumney | 6,236 | Cardiff South and Penarth | 1,387 | 2,483 | 66 | 74 | 26 | 85 | 0 | 15 | 4,136 |
| Cardiff | Splott | 9,446 | Cardiff South and Penarth | 1,413 | 4,267 | 204 | 107 | 56 | 193 | 0 | 25 | 6,265 |
| Cardiff | Trowbridge | 11,504 | Cardiff South and Penarth | 1,971 | 5,056 | 216 | 133 | 76 | 173 | 0 | 6 | 7,631 |
| Total | 90,232 | 14,229 | 38,935 | 4,760 | 805 | 620 | 1,906 | 0 | 59 | 61,314 | ||
And these are the implied results for 2017 for the new seat of Cardiff South and East. Please note that the wards used are those of 2015 in order to be consistent with those used by the Boundary Commissions.
© 2024 Electoral Calculus Ltd
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