The Theory of Production

Total Product (TP) simply means the total output you get from using workers or machines. Average Product (AP) is the total output divided by the number of workers—basically how much each worker produces on average. Marginal Product (MP) is the extra output you gain by adding one more worker.

These three connect perfectly through the Law of Diminishing Returns. Imagine a cassava farmer in Oyo State. With one worker, he harvests 100 bags daily (TP). With two workers, total output becomes 180 bags (TP increases, AP is 90). The second worker added 80 bags, which is the MP. However, as he keeps hiring more workers in the same farm space, each new worker contributes less. Eventually, workers get in each other's way, and MP falls. When MP drops below AP, the AP also starts declining.

Variable proportion refers to the situation where a producer changes the quantity of one input (like labour) while keeping other inputs (like land or machinery) fixed. Think of a cassava farmer who uses the same piece of land but hires more workers during harvest season. As he adds more labourers, output increases, but eventually each additional worker contributes less to production than the previous one—this is the law of diminishing returns. Initially, three workers on the farm might produce more cassava together than working separately because they coordinate better. However, by the tenth worker on the same small plot, there's overcrowding and less efficiency. Understanding this concept helps firms decide the optimal number of workers to employ and explains why production costs eventually rise steeply. This principle applies across Nigerian industries from palm oil processing to textile manufacturing.

When a business grows bigger, it enjoys cost advantages called internal economies of scale. These benefits come from within the company itself—like when a large bakery buys flour in bulk at cheaper prices than a small bakery, or spreads its fixed costs across more products. External economies, however, benefit entire industries in specific locations. Think of Lagos's Lekki Free Trade Zone where multiple manufacturing companies cluster together, sharing infrastructure, skilled workers, and suppliers. When one company benefits from roads, electricity, and trained labour that the whole zone developed, that's an external economy. Both types reduce production costs, but internal economies reward individual firms while external economies reward whole industries developing in the same area.

When a business grows and produces more goods, the cost of making each item usually falls. This is called economies of scale. Think of it like this: a small bakery spends a lot of money buying flour in small quantities, but when it expands and buys flour in bulk, each bag costs less. The same principle applies to factories using machinery more efficiently, getting better prices from suppliers, and spreading fixed costs like rent across more products.

Consider Dangote Cement: as the company expanded production across Nigeria, the average cost per bag of cement decreased significantly. This allowed them to charge competitive prices while earning higher profits. The business achieved this through larger-scale operations, better equipment, and negotiating power with suppliers.

A production function shows the relationship between the inputs a business uses and the output it produces. Think of it as a recipe—combine certain ingredients in specific amounts, and you get a particular dish. There are two main types you must know for JAMB.

The short-run production function describes what happens when some inputs are fixed while others vary. For example, a Lagos bakery might have a fixed oven but can hire more workers. The long-run production function allows all inputs to change. That same bakery could buy additional ovens, expand premises, and hire more staff.

Understanding these types helps you analyze how businesses respond to increased demand. When a company needs more output quickly, it adjusts variable inputs within the short run. Planning for permanent growth requires adjusting all inputs in the long run.

Returns to scale describes what happens to output when you increase all inputs by the same proportion. Imagine a small textile factory in Lagos that doubles its machines, workers, and raw materials. If production more than doubles, that's increasing returns to scale—the business becomes more efficient. If output exactly doubles, that's constant returns to scale, which is most common in mature industries. If output less than doubles, that's decreasing returns to scale, often happening when management becomes difficult as firms grow too large.

Understanding these three types helps explain why some Nigerian businesses succeed when expanding while others struggle. The key is recognizing that returns to scale differ from returns to a single factor, which you must distinguish clearly.

Production operates at different scales: small scale involves limited output using basic equipment (like a local tailor's shop), medium scale uses more advanced methods with moderate capital, and large scale employs modern technology and massive resources (like a large cement factory). When production increases, important things happen. Increasing returns to scale occur when output grows faster than inputs increase, reducing per-unit costs. Constant returns happen when output and inputs grow proportionally. Decreasing returns occur when output grows slower than inputs, raising costs per unit. A Nigerian example is comparing a small pepper seller using only hands versus a large agro-processing company using machines—the large operation produces more cheaply per unit. Understanding these scales helps firms decide their optimal production size and explains why some industries have giant companies while others remain small.

A firm reaches equilibrium when it produces at the level where profits are highest and there's no incentive to change output. This happens where Marginal Revenue (MR) equals Marginal Cost (MC). At this point, the money made from producing one extra unit equals the cost of making that unit, so making more or less would reduce profit.

Think of a Lagos garment factory producing school uniforms. When the factory manager finds that selling one more uniform brings in exactly what it costs to make it, they've hit equilibrium. Beyond this point, each extra uniform costs more to produce than it earns, so profit drops.

The key is understanding that equilibrium isn't about making the most products—it's about making the most money. A firm might produce less but earn higher profits.

The isoquant-isocost framework helps firms determine the cheapest way to produce a given output. An isoquant shows all combinations of labour and capital that produce the same quantity of goods, while an isocost line represents combinations of inputs a firm can afford with a fixed budget.

Think of a Nigerian textile factory needing to produce 1,000 metres of fabric. Management must decide: should they hire more workers (labour) or buy expensive machines (capital)? The isoquant shows all possible combinations that yield exactly 1,000 metres. The isocost line shows what combinations fit their budget. Where these lines touch is the optimal point—maximum output for minimum cost.

This happens where the isoquant's slope equals the isocost line's slope, meaning the firm gets equal productivity per naira spent on each input. Understanding this optimization principle is crucial for production efficiency questions.

Productivity simply means how much output a worker or machine can produce in a given time. Several things determine whether productivity will be high or low. The skill level of workers matters greatly—a trained tailor produces more quality clothes than an untrained one. Technology also plays a big role; a farmer using a tractor produces more than one using a hoe. Capital equipment, good management, and workplace conditions all boost productivity too. When workers have proper tools, fair wages, and safe working environments, they work harder and produce more. Consider a Nigerian cocoa farmer with modern equipment and good training versus one using traditional methods—the difference in output is massive. Even the availability of raw materials affects how much a business can produce. Motivation also counts; workers who feel valued and appreciated tend to be more productive.