Year 13 WJEC Politics: Formula & Theorem Quick Reference Guide | WJEC 政治公式定理速查手册

📚 Year 13 WJEC Politics: Formula & Theorem Quick Reference Guide | WJEC 政治公式定理速查手册

This quick reference guide compiles the essential formulas, theorems, indices, and principles required for Year 13 WJEC Politics. It covers electoral systems, power analysis, party system measurements, rational-choice models, and foundational political theories. Each entry is presented with a concise explanation and the relevant formula or statement, suitable for rapid revision.

本速查手册汇编了 WJEC 政治 Year 13 所需的核心公式、定理、指数和原则。涵盖选举制度、权力分析、政党体系测量、理性选择模型以及基础政治理论。每个条目均附简要说明和相关的公式或陈述，适合快速复习。

1. Droop Quota & Hare Quota | 德鲁普配额与黑尔配额

The Droop quota is used in Single Transferable Vote (STV) elections to determine the minimum number of votes a candidate needs to secure a seat. It ensures that no more candidates can reach the quota than there are seats. The formula is floor(Total Valid Votes / (Seats + 1)) + 1. The Hare quota, Total Votes / Seats, is simpler but can leave more wasted votes.

德鲁普配额用于可转移单票制（STV）选举，决定候选人获得席位所需的最低票数。它确保达到配额的人数不超过席位总数。公式为：⌊总有效票数 / (席位数 + 1)⌋ + 1。黑尔配额为总票数除以席位数，更为简单但可能产生更多废票。

Droop Quota = ⌊ Total Votes / (Seats + 1) ⌋ + 1

Hare Quota = Total Votes / Seats

2. D’Hondt & Sainte-Laguë Formulas | 东特公式与圣拉格公式

These are highest-average methods for allocating seats in proportional representation list systems. In the D’Hondt method, party votes are divided by divisors 1, 2, 3, … (or seats won + 1). The Sainte-Laguë method uses divisors 1, 3, 5, … (or 0.5, 1.5, 2.5… after the first seat). D’Hondt tends to favour larger parties, while Sainte-Laguë is more proportional to smaller parties.

这些都是比例代表制名单系统中分配席位的最高均数法。在东特法中，政党得票数依次除以除数 1、2、3……（或已获席位数 +1）。圣拉格法则使用除数 1、3、5……（或获得一席后使用 0.5、1.5、2.5……）。东特法倾向大党，而圣拉格法对小党更公平。

D’Hondt quotient = Party Votes / (Seats Won + 1)

Sainte-Laguë quotient (first seat) = Party Votes / 1; subsequent quotients = Party Votes / (2 × Seats Won + 1)

3. Effective Number of Parties (Laakso-Taagepera) | 有效政党数（拉克索-塔格佩拉指数）

The effective number of parties measures the number of viable political parties weighted by their vote or seat share. A lower value indicates a more concentrated party system. The formula is N = 1 / Σ pᵢ², where pᵢ is the proportion of votes (or seats) won by party i.

有效政党数根据政党得票或议席占比，衡量有竞争力的政党数量。数值越低表明政党体系越集中。公式为 N = 1 / Σ pᵢ²，其中 pᵢ 是政党 i 获得的选票（或席位）比例。

N