3. Microeconomic decision-makers

Central-bank action matters because stable prices protect purchasing power, supervision and emergency liquidity reduce the risk of bank collapse, and monetary policy influences borrowing, spending and economic activity.

Commercial banks connect savers with borrowers and make payments possible. More sound lending can finance consumption and business investment; investment can raise capacity, productivity, employment and output. The benefit depends on borrowers being able to repay and banks assessing risk well.

Use a three-link explanation: identify the influence, state how it changes purchasing power, reward, cost or perceived risk, then give the direction of spending, saving or borrowing. For example: lower confidence → greater fear of income loss → less spending and borrowing, with more precautionary saving.

A higher wage raises purchasing power, but it may not compensate for danger, insecurity, long training or inconvenient hours. A lower-paid job can be preferred when it offers stability, safer conditions, better hours or greater satisfaction.

For a labour-market diagram, put wage rate on the vertical axis and quantity of labour on the horizontal axis. Label demand and supply, mark the original equilibrium, shift only the curve whose determinant changes, and show the new wage and employment. A movement along a curve is not a shift.

A trade union represents workers and bargains collectively over pay and conditions. Its bargaining power is stronger when membership is high, workers are hard to replace, the firm is profitable, labour is important to production and industrial action is credible; it is weaker when unemployment or automation provides substitutes.

A national minimum wage is a legal wage floor. If set above equilibrium, quantity of labour supplied exceeds quantity demanded, so unemployment may rise; firms may substitute machines or reduce output. Higher pay can also improve motivation, productivity and demand. If set at or below equilibrium, it is non-binding and has no direct effect.

Skill normally raises productivity and restricts supply, but sector labels alone do not determine pay: primary, secondary and tertiary occupations each contain high- and low-paid work. Public-sector wages may follow government pay scales and budgets; private-sector wages may respond more directly to profit, revenue and firm bargaining.

Explain a gap as a chain: identify the worker or occupation difference → show its effect on demand, supply or bargaining → state the wage direction. Keep discrimination separate from differences caused by productivity, experience or hours.

Whether workers benefit depends on how productivity gains are shared through wages, hours and conditions, and whether job variety, security and training improve or worsen. Firms benefit only if coordination savings exceed supervision, breakdown and motivation costs.

Private firms may respond strongly to profit and competition; public firms may prioritise access, affordability and social costs or benefits. Neither ownership type is automatically more efficient—the outcome depends on competition, objectives, finance and management.

Any merger may spread fixed costs, raise finance, invest or compete internationally. It may also create diseconomies, culture clashes, duplicated jobs, debt and complacency. Horizontal mergers deserve special scrutiny because reduced rivalry can lower choice, quality and efficiency.

For the long-run ATC diagram, put average total cost on the vertical axis and output/scale on the horizontal axis. Draw a U-shaped ATC curve: its downward section shows economies of scale, the lowest region shows minimum average cost, and its upward section shows diseconomies. Mark two outputs and read their ATC values to interpret the direction.

Internal economies or diseconomies describe movement along the long-run ATC curve as the firm changes scale. External economies shift the whole ATC curve downward because every output level becomes cheaper; external diseconomies shift it upward.

If demand for bread rises, a bakery may demand more bakers and ovens. If ovens become cheaper and work well with trained bakers, demand for both capital and skilled labour can rise; if machines replace a repetitive task, demand may shift from routine labour towards capital.

A restaurant may retain skilled chefs because variety and personal quality matter, while a food-processing plant may automate repetitive high-volume stages. A mixed method is common: machines provide speed and consistency while workers supervise, maintain and adapt the process.

A farm's harvest rises from 100 to 120 tonnes after labour rises from 10 to 12 workers: production rises, but output per worker stays at 10 tonnes. If 10 workers instead produce 120 tonnes, production rises and labour productivity rises to 12 tonnes per worker.

Investment in suitable capital can give workers faster or more accurate equipment; investment in education and training can build the skills needed to use it. Productivity then rises through more or better output from each input. The gain may be delayed by installation and training, and weak if equipment is unsuitable, idle or poorly maintained.

For a total-cost diagram, place cost on the vertical axis and output on the horizontal axis. FC is horizontal above zero. VC normally begins at the origin and rises with output. TC begins at the FC intercept and remains vertically above VC by exactly FC because TC − VC = FC.

For an average-cost diagram, AFC falls as output rises because the same fixed cost is spread over more units. At each output, the vertical gap between ATC and AVC equals AFC. Read a curve value at the chosen output before comparing costs; a falling average can coexist with a rising total.

If every unit is sold at one price, AR equals that price. For example, sales of 50 units at $3 each give TR of$150 and AR of $3.

Use quantity actually sold, not merely produced. If price is unchanged, more sales raise TR in direct proportion. If price and sales both change, calculate price × quantity for each situation before deciding the revenue effect.

Here sales fall by 400 units but TR rises by $1000 because the higher price more than offsets the lower quantity sold. AR rises to$10 because each sold unit brings in $10.

A new small firm may prioritise survival, a state-owned health provider may prioritise social welfare, and an established private firm may emphasise profit or growth. These are plausible priorities, not automatic rules based only on ownership.

Consumers often gain purchasing power, choice and responsiveness to demand. Firms may become more efficient and innovative, but can face advertising costs, uncertain sales, closure risk and less finance for investment. The effect depends on costs, product differences and how strongly buyers switch.

Consumers may benefit when scale lowers cost, profit funds research or a state-owned monopoly prioritises social welfare. They may lose when market power produces high prices, weak service or complacency. Judge whether lower costs and investment are actually passed on through price, quality or access.