Subsection (1) provides that all candidates to be returned as constituency members within an electoral region must be determined before the return of the regional members for that region.  This is because the regional member seats are allocated on a corrective basis, taking account of the number of constituency seats a party has gained.
This was modified by Rule 70 in Schedule 2 of the Scottish Parliament (Elections etc.) Order 1999 (S.I. 1999/787) to deal with the situation where a candidate dies before a result is returned.  “Constituencies included in the region” is to be construed as reference to all of the constituencies included in the region except those in relation to which rule 70(1) applies.
Subsection (2) provides that, for each registered political party which has submitted a list of candidates, the number of regional votes recorded in each constituency throughout the region are added together and divided by the number of constituency seats gained plus one.  Parties who do not gain any constituency seats can be involved in the calculations.  The resultant figure is called the “regional figure”.  Taking constituency seats into the calculations means that additional seats are allocated correctively as opposed to on a simple proportional basis. In other words, a party, which has won disproportionately few constituency seats having regard to their regional vote, may be compensated by being allocated additional seats from the party’s regional list.  However, only the regional vote is used in the calculation; votes cast in the ballot for constituency members are disregarded for this purpose.
Subsection (3) provides that each time a party gains a regional member seat the “regional figure” for that party is recalculated taking into account the seat thus gained by adding it to the divisor i.e. the previous aggregate number of constituency seats gained by the party plus one.
Subsection (4) provides that the “regional figure” for individual candidates is simply the total number of regional votes cast for the individual in each constituency in the region.  By virtue of section 8(3), any individual candidate who has been returned as a constituency member is disregarded when allocating regional seats.
Commentary Details of Provisions