Understanding LIFO in a Rising Price Environment

The Last-In, First-Out (LIFO) method is an inventory valuation technique used by companies. It assumes that the last units of inventory purchased are the first ones sold. This assumption affects how the cost of goods sold (COGS) and ending inventory are calculated.

Let's analyze what happens when prices are rising under the LIFO method.

LIFO Explained with Rising Prices

Imagine a company buys inventory at different prices over time, and these prices are increasing:

• First purchase: 10 units at $5 each
• Second purchase: 10 units at $6 each
• Third purchase: 10 units at $7 each

Now, the company sells 15 units. Under the LIFO method, the assumption is that the units most recently purchased are sold first.

• The 10 units from the third purchase (costing $7 each) are considered sold first.
• Then, 5 units from the second purchase (costing $6 each) are considered sold next.

Impact on Cost of Goods Sold (COGS)

The cost of the 15 units sold under LIFO is calculated as follows:

• 10 units × $7 = $70
• 5 units × $6 = $30
• Total COGS = $70 + $30 = $100

Since the most recently purchased units (which have the highest costs in a rising price environment) are assumed to be sold, the Cost of Goods Sold will be higher under LIFO compared to other methods like FIFO (First-In, First-Out) where the older, lower-cost units would be assumed sold first.

Therefore, in a period of rising prices, LIFO produces the highest cost flow (highest COGS).

Impact on Ending Inventory

After selling 15 units, the remaining inventory is:

• The 10 units from the first purchase (costing $5 each).
• The remaining 5 units from the second purchase (costing $6 each).

The value of the ending inventory under LIFO is calculated as follows:

• 10 units × $5 = $50
• 5 units × $6 = $30
• Total Ending Inventory = $50 + $30 = $80

Since the oldest units (which have the lowest costs in a rising price environment) are assumed to be remaining in inventory, the value of the ending inventory will be lower under LIFO compared to methods like FIFO, where the newer, higher-cost units would be assumed to be remaining.

Therefore, in a period of rising prices, LIFO produces the lowest inventory value.

Summary Comparison (Rising Prices)

In summary, when prices are rising, the LIFO method assigns the most recent, highest costs to the cost of goods sold, resulting in the highest cost flow. Conversely, the oldest, lowest costs remain in ending inventory, resulting in the lowest inventory value.

Thus, when prices are rising, the LIFO method produces the highest cost flow and lowest inventory.

Revision Table: LIFO and Rising Prices

Additional Information: Inventory Valuation Methods

Inventory valuation methods determine the cost of inventory and cost of goods sold. Besides LIFO and FIFO, another common method is the Weighted-Average Cost method.

• First-In, First-Out (FIFO): Assumes the first units purchased are the first ones sold. In rising prices, this results in lower COGS and higher ending inventory.
• Last-In, First-Out (LIFO): Assumes the last units purchased are the first ones sold. In rising prices, this results in higher COGS and lower ending inventory. (Note: LIFO is permitted under U.S. GAAP but not under IFRS).
• Weighted-Average Cost: Calculates a weighted average cost for all inventory items and uses that average to determine the cost of goods sold and ending inventory. This method results in COGS and ending inventory values between those of LIFO and FIFO in periods of changing prices.

The choice of inventory method impacts a company's reported profitability and financial position, especially during periods of inflation or deflation.