經濟,財務,統計學,數理科學與政治評論

Hello there:

  在製造業與流通業會計中,Inventory management是非常重要的!!

  存貨方程式:期初存貨+本期購買=銷貨成本+期末存貨

  i.e.,Beginning Inventory + Purchase = COGS + Ending Inventory

簡單的說,我們從上式已經知道,COGS多時,Ending Invenroty少;同樣地,COGS少時,Ending Inventory多!!這是非常重要的觀念,因為存貨將影響到Current Asset與Current Ratio,而COGS則影響到Net income,兩者將共同影響到ROE和ROA!!

  現在讓我們來看一下兩種不同的存貨處理FIFO(First In, First Out)與LIFO(Last In, First Out),這是美國U.S. GAAP所獨有的,IFRS中並不允許LIFO的使用...在U.S.GAAP下,我們知道

     Inventory(FIFO) = Inventory(LIFO) + LIFO reserve (定義)

 (1)所以當前期存貨已知,今有兩條path須考量,一個為FIFO的採用,另一個為LIFO的採用....

      BI(FIFO) + Purchase = COGS (FIFO) + EI (FIFO)

      BI(LIFO) + Purchase = COGS (LIFO) + EI (LIFO)

將兩者相減,我們知道

   Diff Inventory (FIFO) = Diff Inventory (LIFO) + Diff LIFO reserve

   COGS (LIFO) - COGS (FIFO) 

       = 本期 LIFO reserve 的差額 (定義)

       = Diff LIFO reserve

 to be simple, we write

   COGS(LIFO, t) = COGS (FIFO, t) + Diff. LIFO Reserve(t)

 (2)讓我們回頭複習一下operating Income (EBIT)的由來,

   Operating Income = Sales - COGS +/- other items,

 因此當COGS高時, EBIT就會低;同樣地, COGS低時,EBIT 就會高!!

 由此我們知道在inflation environment下,

 Inventory (LIFO) 的價值小於 Inventory (FIFO)

  (而COGS(LIFO) > COGS(FIFO),因此Net income(LIFO) < Net Income(FIFO)

   這救是為何企業喜歡LIFO的原因,因為tax burden少!!)

 EBIT (LIFO) < EBIT (FIFO),但因為LIFO繳的稅少,能保留的現金多,

 反倒使其CFO較多 , CFO(LIFO) > CFO(FIFO)!!

  Cash saved = Cash (LIFO) - Cash (FIFO)

             = Diff LIFO reserve * tax rate

 而

  Net Income (FIFO)

  = Net Income (LIFO) + Diff LIFO reserve *(1-tax rate)

  (3)有用的小結論:

    別忘記,在會計上面,資產負債表中的科目都是存量的概念,

    而損益表中的科目都是流量的概念;

  因此在這裡當存貨制度由LIFO 轉換成FIFO時,我們知道....

  在I/S中, 其COGS, Taxes saved與 Net income均與 Diff LIFO reserve有關;

  在B/S中, 其 Inventory, Cash, Equity均與 LIFO reserve有關!!

  (4)其他重要的會計數據:

  1. Inventory Turnover = COGS / Average inventory

  2. Return on Assets = Net Income / Average Assets

  3. Return on Equity = Net Income / Average Equity

  4. Current Ratio = Current Asset/ Current Liability

  在 Inventory turnover中,我們採用

   COGS(LIFO) = COGS(FIFO) + Diff LIFO reserve

  在ROA與CR中,

  Assets (FIFO)

   = Asset (LIFO) + LIFO reserve - Diff Income Taxes

where

  Diff Income Taxes (t) 

   = Summation(t) ( Diff LIFO reserve(t) * tax rate (t) )

   = LIFO reserve (t-1)*tax rate [ave(1 ~ (t-1))]

     + Diff LIFO reserve(t) * tax rate(t)

  同理

   Current Asset (FIFO)

  = Current Asset (LIFO) + LIFO reserve - taxes savings

  其中

    taxes savings = Diff Income Taxes

  (F)因此我們有幾個重要的結論:

   B/S:

   Inventory (FIFO) = Inventory (LIFO) + LIFO reserve

   Cash (FIFO) = Cash (LIFO) - LIFO reserve * tax rate

   Equity (FIFO) = Equity (LIFO) + LIFO reserve * (1- tax rate)

   I/S:

    COGS (FIFO) = COGS (LIFO) - Diff LIFO reserve

    Taxes (FIFO) = Taxes (LIFO) + Diff LIFO reserve * tax rate

    Net Income (FIFO) = Net Income (LIFO) + Diff LIFO reserve * (1-tax rate)

 這些式子都是用來計算之用的!!!