Stock Valuation: Methods and Principles

Stock valuation is the process of assigning a monetary value to the inventory or stock held by a business at the end of an accounting period. Proper valuation is essential because stock represents a significant current asset and directly impacts the calculation of the Cost of Goods Sold (COGS) and Gross Profit.

1. Methods of Cost Determination

In a period of changing prices, it is difficult to identify which specific unit was sold. Therefore, accounting methods are used to determine costs:

• FIFO (First-In, First-Out): This method assumes that the items of stock purchased first are the first ones to be sold. Therefore, the closing stock consists of the most recently purchased items.
• LIFO (Last-In, First-Out): This method assumes that the items purchased most recently are the first ones to be sold. Closing stock consists of the oldest items. Note: LIFO is generally not permitted under International Financial Reporting Standards (IFRS) but remains part of the JAMB syllabus for comparative study.
• Simple Average Method: This involves calculating the arithmetic mean of the prices at which goods were purchased, regardless of the quantity in each batch.

2. The Importance of Stock Valuation

• Determination of Profit: According to the Trading Account equation, Closing Stock is deducted from the total goods available for sale. Overstating closing stock leads to an overstatement of profit.
• Balance Sheet Accuracy: Stock is a current asset. Accurate valuation ensures that the business's liquidity and net worth are correctly stated.
• Taxation: Higher reported profits lead to higher tax liabilities. Choosing a valuation method can influence the tax paid in a specific period.

3. Advantages and Disadvantages

FIFO

Advantages: It is logical, reflects actual flow in most businesses (e.g., perishables), and closing stock is valued at recent market prices.
Disadvantages: In times of inflation, it results in higher taxes because reported profit is high.

LIFO

Advantages: Matches current costs against current revenues; during inflation, it results in lower taxes due to lower reported profit.
Disadvantages: Closing stock is valued at outdated prices; it is not accepted by many tax authorities.

Simple Average

Advantages: Easy to calculate; smooths out price fluctuations.
Disadvantages: It ignores the physical quantity of goods in each purchase batch, which can lead to distorted unit costs.

4. Effects on Profit and Cost of Goods Sold (COGS)

The relationship is defined by: COGS = Opening Stock + Purchases - Closing Stock. If closing stock is high (as in FIFO during inflation), COGS will be low, and Gross Profit will be high. Conversely, if closing stock is low (LIFO during inflation), COGS will be high, and Gross Profit will be low.