房地產市場的供應量

房 地 產 市 場 較 其 他 商 品 市 場 容 易 預 測 ， 其 中 一 個 原 因 是 房 地 產 市 場 的 供 應 量 較 其 他 商 品 市 場 容 易 預 測 。 
樓 宇 作 為 一 種 商 品 ， 其 特 色 是 生 產 期 很 長 ， 由 開 工 到 落 成 起 碼 需 要 兩 三 年 ， 我 們 可 以 根 據 市 場 上 有 幾 多 地 盤 正 在 開 工 ， 以 及 他 們 施 工 的 進 度 ， 粗 略 估 計 到 未 來 一 兩 年 的 供 應 量 。 市 場 由 供 求 組 成 ， 能 了 解 供 應 的 情 況 ， 也 就 了 解 了 市 場 的 一 半 。 
話 雖 如 此 ， 即 使 能 掌 握 全 面 資 料 的 政 府 ， 也 不 能 準 確 地 預 測 房 地 產 市 場 的 供 應 。 差 餉 物 業 估 價 署 每 年 都 公 布 對 樓 宇 供 應 量 的 預 測 ， 但 一 樣 常 有 超 過 百 分 之 二 十 的 誤 差 。 原 因 是 地 產 商 會 不 斷 地 按 照 市 場 的 情 況 調 整 他 們 的 建 設 速 度 ； 市 好 時 ， 盡 量 建 得 快 一 點 ； 市 差 時 ， 就 拖 慢 來 建 ， 以 待 更 好 的 時 機 。 
此 外 ， 樓 宇 的 供 應 量 亦 受 天 氣 及 勞 工 市 場 的 情 況 影 響 ， 打 風 落 雨 多 的 日 子 ， 施 工 的 進 度 自 不 然 會 拖 慢 ； 而 當 大 型 基 建 工 程 進 行 時 ， 亦 會 影 響 建 築 工 人 的 供 應 ， 引 致 工 程 未 能 如 期 完 成 。 
香 港 媒 體 對 樓 宇 供 應 量 的 定 義 很 模 糊 ， 一 時 指 樓 宇 的 落 成 量 ， 一 時 指 新 盤 的 開 盤 量 ， 令 人 摸 不 著 頭 腦 。 
差 餉 物 業 估 價 署 一 般 只 對 樓 宇 的 落 成 量 作 出 估 計 。 這 是 從 用 家 的 角 度 著 眼 的 。 因 為 樓 宇 要 落 成 才 可 以 用 ， 才 可 以 真 正 滿 足 用 家 的 需 求 。 再 者 ， 落 成 量 是 更 根 本 性 的 ， 有 多 少 新 盤 可 開 亦 取 決 於 將 有 多 少 樓 宇 會 落 成 。 
然 而 ， 以 市 場 的 直 接 反 應 來 說 ， 開 盤 量 的 影 響 遠 比 落 成 量 為 大 。 譬 如 ， 九 九 年 的 落 成 量 將 超 過 三 萬 個 ， 是 近 幾 年 來 最 高 的 。 但 由 於 九 八 年 樓 花 銷 售 量 相 當 多 ， 不 少 九 九 年 落 成 的 樓 宇 早 在 九 八 年 已 賣 出 ， 故 即 使 落 成 量 大 ， 對 市 場 的 壓 力 也 不 會 太 大 。 因 此 ， 我 們 不 能 簡 單 地 以 為 落 成 量 高 的 日 子 ， 樓 價 一 定 會 回 落 。