Cost of Production: Meaning, Types, Short-Run Schedules & Curves
Understand how cost analysis drives modern production. Learn the distinction between business costs and economic costs (Explicit, Implicit & Normal Profit), evaluate Private vs. Social costs, analyze short-run fixed and variable costs, and master per-unit metrics (AFC, AVC, ATC) and Marginal Cost (MC).
1. Definition of Cost & Economic Cost Categories
Cost of Production is defined as the expenditure incurred by a firm or producer to purchase or hire factors of production (land, labour, capital, entrepreneurship) and non-factor inputs (raw materials, fuel, electricity) required to produce a commodity.
Cost Function Formula:
Actual out-of-pocket payments made by a producer to purchase or hire factor services and inputs from the market. (e.g., Wages to workers, rent for building, raw material payments, electricity bills).
Estimated market value of self-owned and self-supplied inputs used in production. (e.g., Imputed rent of self-owned factory building, interest on self-invested capital, salary for own management).
Minimum assured return required by an entrepreneur to remain in the current business rather than shifting to the next best alternative occupation. It represents reward for bearing risk and uncertainty.
(Note: Business Accounting considers ONLY Explicit Costs, whereas Microeconomics includes all three!)
Practical Example: Cost Breakdown for a Rice Farmer
| Explicit Cost Elements (Paid Out) | Implicit Cost Elements (Self-Provided) | Normal Profit |
|---|---|---|
| • Fertilizers & Insecticides purchase | • Imputed rent of his own land | • Minimum remuneration/return required to induce the farmer to cultivate rice instead of switching to another crop. |
| • Wages for hired agricultural workers | • Imputed water value from his own well | |
| • Rent paid for hired tractor & harvester | • Own saved seeds from previous harvest | |
| • Electricity charges for tube-well pump | • Unpaid labour of farmer & family members |
2. Private vs. Social Cost & Money vs. Real Cost
Private Cost vs. Social Cost
Direct financial expenses incurred by an individual firm to produce a commodity (wages, raw materials, rent).
Total cost borne by the community/society due to production. Includes private costs PLUS external costs like smoke pollution, health expenses, and laundry bills caused by industrial emissions.
Money Cost vs. Real Cost
Expenditures actually incurred or expressed in monetary currency terms (e.g., ₹1000 wage payment, ₹500 rent).
Non-monetary sacrifices, pain, discomfort, mental stress, toil, and physical strain underwent by producers and factor owners during the production process.
3. Short-Run Costs: Total Fixed Cost (TFC), Total Variable Cost (TVC) & Total Cost (TC)
In the short run, production factors are divided into Fixed Factors (plant, building, machinery) and Variable Factors (labour, raw materials).
Expenditure on fixed inputs. Remains constant at ALL output levels, even at zero output. Represented by a horizontal straight line parallel to the output axis. Also called supplementary/overhead costs.
Expenditure on variable inputs. Equals ZERO at zero output and increases as output expands. Also known as direct or prime costs.
Sum of TFC and TVC. At zero output, TC equals TFC. Increases directly as output increases due to changes in TVC.
Textbook Table 18.2: Pen Producer Short-Run Cost Schedule
| Output of Pens (units: 1 unit = 100 pens) | Total Fixed Cost (TFC) (₹) | Total Variable Cost (TVC) (₹) | Total Cost (TC = TFC + TVC) (₹) |
|---|---|---|---|
| 0 | 60 | 0 | 60 |
| 1 | 60 | 60 | 120 |
| 2 | 60 | 100 | 160 |
| 3 | 60 | 150 | 210 |
| 4 | 60 | 260 | 320 |
| 5 | 60 | 390 | 450 |
4. Per-Unit Costs (AFC, AVC, ATC) & Marginal Cost (MC)
Per-unit fixed cost. Continuously declines as output expands because fixed cost is distributed over more units. Graphically forms a rectangular hyperbola.
Per-unit variable cost. Initially falls, reaches a minimum, and then rises due to the law of variable proportions (U-shaped curve).
Per-unit total cost. U-shaped curve resulting from the vertical sum of AFC and AVC curves.
Addition made to total cost (or total variable cost) by producing one extra unit of output. Dependent strictly on variable costs.
Textbook Table 18.3 & 18.5: Complete Per-Unit & Marginal Cost Schedule
| Output (Q) | TFC (₹) | TVC (₹) | TC (₹) | AFC (₹) | AVC (₹) | ATC (₹) | MC (₹) |
|---|---|---|---|---|---|---|---|
| 0 | 60 | 0 | 60 | - | - | - | - |
| 1 | 60 | 60 | 120 | 60 | 60 | 120 | 60 |
| 2 | 60 | 100 | 160 | 30 | 50 | 80 | 40 |
| 3 | 60 | 150 | 210 | 20 | 50 | 70 | 50 |
| 4 | 60 | 260 | 320 | 15 | 65 | 80 | 110 |
| 5 | 60 | 390 | 450 | 12 | 78 | 90 | 130 |
5. Interrelationships between AC, AVC, and MC Curves
(a) Relationship between AC and MC
- When MC < AC: AC falls as output increases.
- When MC = AC: AC is at its minimum and remains constant.
- When MC > AC: AC rises as output increases.
- Key Takeaway: MC curve cuts the AC curve from below at its lowest (minimum) point.
(b) Relationship between AVC and MC
- When MC < AVC: AVC falls as output increases.
- When MC = AVC: AVC is at its minimum and remains constant.
- When MC > AVC: AVC rises as output increases.
- Key Takeaway: MC curve cuts the AVC curve from below at its minimum point before cutting AC.