ECN1023 Economic Behaviour and Decision Making Notes (UJ)

ECN1023 Economic Behaviour and Decision Making explores how people actually make choices under scarcity, uncertainty, emotion, social pressure, and limited information. At the University of Johannesburg, the topic is especially useful because it connects core microeconomic reasoning with real human behaviour, helping students understand why decisions often deviate from the perfectly rational model taught in introductory economics. These notes bring together classical theory, behavioural economics, choice architecture, biases, incentives, risk, and applications to everyday and policy decisions.

1. Foundations of Economic Behaviour and Decision Making

Economic behaviour begins with a simple fact: resources are limited, while wants are not. Every individual, household, firm, and government must choose among alternatives, and the quality of those choices depends not only on prices and income, but also on psychology, expectations, habits, and social context. In ECN1023, economic behaviour is not treated as a narrow mathematical exercise; it is studied as a practical process in which people try to satisfy goals under constraints. This is why decision making sits at the centre of the module. It explains why the same market conditions can lead different people to make different choices, and why the same person may make inconsistent choices over time.

Scarcity, choice, and opportunity cost

Scarcity is the starting point of economics. Because time, money, attention, and energy are limited, choosing one option always means giving up another. That forgone alternative is the opportunity cost. Students often think opportunity cost only means “the price paid,” but in economic decision making it includes the value of the best alternative not chosen. If a student spends R500 on a night out, the real cost may also include textbooks, transport, data, or savings they could have used instead. If a firm uses a delivery van for one route, it cannot use that same van elsewhere during the same period. If government spends on roads, it gives up spending on clinics or schools.

Opportunity cost matters because rational decision making compares marginal benefit and marginal cost. A decision is worthwhile if the additional benefit exceeds the additional cost. This principle applies to almost all economic choices, from buying a single item to entering a market or investing in education. Yet real decisions are rarely perfectly calculated. People often make “good enough” decisions because they lack time, information, or cognitive capacity.

Rational choice and its limits

The traditional economic model assumes rational choice. Under this model, a decision maker:

1. has clear preferences,
2. ranks alternatives consistently,
3. knows the relevant prices and constraints,
4. chooses the option that maximises utility or profit.

This model is powerful because it gives a clear benchmark. It helps economists predict behaviour under incentives and compare outcomes across policies. However, ECN1023 also emphasises that real people are not perfectly rational in the strict neoclassical sense. Their preferences may be unstable, their information incomplete, and their attention limited. They may respond strongly to framing, default options, peer influence, or emotions such as fear and regret.

The point is not that rational choice is useless. Rather, it is a useful normative and analytical starting point, but it must be complemented by behavioural insights. A student deciding whether to study or watch television may understand the long-term benefit of studying, yet still procrastinate because the immediate gratification of entertainment is more tempting than the delayed benefit of higher marks. A consumer may know that saving is wise, but still overspend due to present bias or advertising.

Utility, satisfaction, and preferences

Economists use the term utility to describe satisfaction or well-being derived from a choice. Utility does not mean happiness in a simple emotional sense; it is a way of representing preferences. A person may derive utility from consumption, safety, status, social belonging, or convenience. Utility helps explain why choices differ between individuals and across contexts.

Preferences can be:

• stable or changing,
• complete or incomplete,
• transitive or inconsistent,
• self-regarding or other-regarding.

A stable and consistent preference set allows straightforward analysis. But in reality, people often experience preference reversals. For example, a student may say they prefer saving money, yet when payday arrives they choose immediate spending over saving. Similarly, a consumer may prefer healthy food in principle but choose fast food when tired, busy, or emotionally stressed. Such patterns matter because they show that decisions are shaped not only by preferences, but by the timing and context of choice.

Rationality in everyday decision making

In everyday life, rationality is often bounded by practical constraints. A commuter in Johannesburg choosing between a bus, train, taxi, or ride-hailing app does not evaluate every possible future state of the world. Instead, they use past experience, perceived safety, time reliability, and budget. A parent buying groceries may not calculate utility formally, but they still compare trade-offs between cost, quality, quantity, and family needs. A firm may not solve an optimisation problem in a textbook way, but it still responds to demand, costs, and competitive pressure.

Economic behaviour therefore includes:

• market choices, such as buying and selling;
• non-market choices, such as time allocation and household production;
• strategic choices, such as bargaining, cooperation, and competition;
• policy-relevant choices, such as voting, compliance, and tax behaviour.

The practical lesson is that economics studies behaviour under constraint, not simply prices. That broader view is essential for understanding real decision making in South African contexts, where income inequality, transport costs, unemployment, and risk strongly shape behaviour.

The importance of incentives

An incentive is anything that changes the attractiveness of an action. Price cuts, subsidies, fines, wages, deadlines, social approval, and recognition can all alter behaviour. Incentives are central because people often react to expected consequences rather than abstract principles. If the price of electricity rises, households may reduce usage. If the penalty for late submission increases, some students submit assignments on time. If a company offers performance bonuses, employees may increase effort.

However, incentives can also produce unintended effects. When an incentive is too strong, it may encourage short-termism, cheating, or risk-taking. For example, sales staff paid only on commission may push unsuitable products. Drivers rewarded purely for speed may compromise safety. In public policy, poorly designed incentives may create gaming behaviour, where individuals manipulate the system rather than improve real outcomes. ECN1023 therefore treats incentives as powerful but not automatically beneficial.

2. Behavioural Economics: Why People Deviate from the Standard Model

Behavioural economics explains systematic departures from the standard rational model. Rather than assuming that people always maximise utility flawlessly, behavioural economics studies how real choices are affected by cognitive shortcuts, emotions, framing, and social norms. The field is important because many everyday decisions are not made by fully calculating all alternatives. Instead, people rely on heuristics — mental rules of thumb — that are useful but imperfect. These shortcuts save time and effort, but they can create bias.

Bounded rationality

The concept of bounded rationality, associated with Herbert Simon, recognises that people have limited information, limited time, and limited computational ability. Instead of maximising perfectly, they often satisfice: they choose an option that is good enough. This is not irrational in a practical sense. It is often the best possible strategy under real-world constraints.

For example, a student choosing accommodation may not inspect every available residence in Johannesburg. They may shortlist a few options based on location, safety, price, and transport access, then choose the first acceptable one. A shopper may compare only a handful of brands before buying. A business owner may use a rough rule for pricing rather than a full demand model. These behaviours reflect bounded rationality, not absence of intelligence.

Bounded rationality is especially relevant where:

• information is costly to gather,
• decisions are repeated frequently,
• consequences are uncertain,
• attention is divided.

Heuristics and biases

Heuristics are decision shortcuts. They are not inherently bad, but they can produce bias when used inappropriately. Common biases in economic decision making include:

• Availability bias: judging likelihood based on how easily examples come to mind. After hearing about a taxi accident, a commuter may overestimate travel risk.
• Anchoring bias: relying too heavily on an initial number. If a product is first shown at R1,500 and then discounted to R999, the R1,500 anchor can make the lower price look attractive even if the item is still expensive.
• Confirmation bias: seeking information that supports existing beliefs while ignoring contradictory evidence.
• Loss aversion: losses feel more painful than equivalent gains feel pleasurable.
• Overconfidence: overestimating one’s knowledge, ability, or likelihood of success.
• Present bias: giving extra weight to immediate rewards relative to future rewards.
• Status quo bias: preferring to keep things unchanged even when alternatives may be better.

These biases matter because they shape consumption, saving, investment, health choices, and study habits. A learner may postpone revision because future exams feel distant. An investor may hold onto a losing asset too long because selling would make the loss “real.” A household may fail to switch to a cheaper service provider because the effort of comparing options feels too high.

Framing effects and choice presentation

Framing refers to the way options are presented. The same outcome can be perceived differently depending on wording, reference point, or context. If a medicine is described as having a 90% survival rate, people respond more positively than if it is described as having a 10% mortality rate, even though the information is equivalent. In consumer markets, “save R200” and “pay only R800” can affect demand differently, even when the final cost is the same.

In economic behaviour, framing matters because people do not only respond to substance; they respond to presentation. Policies and marketing strategies often exploit this. A monthly subscription may appear more affordable than an annual fee, even if the annual total is higher. A “limited-time offer” creates urgency. A “recommended choice” labels one option as socially endorsed. These techniques change behaviour without changing the underlying product itself.

Mental accounting

Mental accounting refers to the tendency to separate money into different psychological categories rather than treating all money as fully interchangeable. People may have a “rent account,” a “fun money” budget, a “savings pot,” and an “emergency fund,” even when economically all money is fungible. This can be helpful for budgeting, but it can also lead to irrational spending.

For example, a person may spend a bonus more freely than regular salary because it is mentally coded as “extra” money. A student may use a refund to buy luxury items rather than settle debt, even though debt repayment could yield a better long-term benefit. Mental accounting explains why people do not always behave according to the pure wealth-maximisation model.

Emotions in decision making

Economics once treated emotions as external to rational choice, but behavioural economics shows that emotions are integral to many decisions. Fear can cause excessive caution, anger can increase risk-taking, regret can shape future choices, and pride can support discipline. Emotions are not random noise; they are part of the decision environment.

For example:

• fear of unemployment may make workers accept poor conditions,
• anxiety about loss may make investors overly conservative,
• pride in family responsibility may encourage saving,
• shame about debt may reduce the likelihood of seeking help early.

In many South African households, economic decisions are not just about individual utility. They are tied to family obligations, social status, and community expectations. An employed family member may support relatives, making consumption and saving decisions more complex than the standard individual model suggests.

Why behavioural economics matters for ECN1023

Behavioural economics matters because it helps explain actual outcomes in markets and policy. If people were fully rational, many simple nudges would have no effect. Yet defaults, reminders, simplification, and timing often matter greatly. This means that institutions can influence outcomes by changing the decision environment. For students, this is crucial: the module is not asking whether people “should” be rational, but how they actually decide, why errors happen, and how policy or business can respond.

3. Consumer Choice, Demand, and Decision Constraints

Consumer behaviour is one of the clearest places to observe economic decision making. Every purchase reflects a trade-off between desire and constraint. Consumers must balance price, income, preferences, quality, waiting time, risk, and social considerations. ECN1023 studies this process to explain demand patterns and the factors that influence what people buy, how much they buy, and when they buy.

Budget constraints and consumption choices

A consumer’s budget constraint limits the combinations of goods and services they can afford. If income is fixed, spending more on one item means spending less on another. The budget constraint is not only about absolute affordability; it is also about relative prices. When the price of one good rises, consumers may substitute toward a cheaper alternative.

For instance, if a household spends most of its monthly income on transport, food, rent, and data, a sudden increase in transport costs may force cutbacks elsewhere. They may reduce restaurant spending, buy cheaper groceries, or delay non-essential purchases. A student with limited allowance may prioritise textbooks and transport over entertainment. These are not just financial calculations; they are lived choices under scarcity.

Demand, marginal utility, and diminishing satisfaction

Demand reflects willingness and ability to buy. Classical consumer theory explains demand using utility maximisation. Consumers allocate spending so that the last rand spent on each good yields similar marginal utility. The law of diminishing marginal utility states that each additional unit of a good usually brings less extra satisfaction than the previous one. The first slice of pizza may be highly satisfying, while the fifth slice may add very little.

This idea explains why consumers diversify their spending rather than buying only one product. It also explains why discounts can stimulate demand: if the price falls, the marginal benefit relative to cost increases. But the behavioural approach adds an important caveat: consumers do not always calculate marginal utility precisely. Instead, they use preferences, habits, and heuristics.

Substitution, income effects, and real-world decisions

When the price of a good changes, demand responses can be understood through the substitution effect and the income effect. The substitution effect occurs when a good becomes relatively more expensive and consumers switch to alternatives. The income effect occurs because a price change effectively alters purchasing power. If food prices rise, the consumer feels poorer and may buy less of many goods, not just the one that became more expensive.

These effects are highly relevant in South Africa, where inflation in food, fuel, electricity, and transport can quickly alter household behaviour. A rise in petrol prices can affect taxi fares, delivery costs, and the prices of other goods. Consumers may respond by changing shopping locations, reducing travel, consolidating trips, or shifting to cheaper brands. Some may delay purchases of durable goods such as appliances or electronics.

Search, information, and consumer uncertainty

Consumers do not operate with perfect information. They may not know product quality, future prices, hidden fees, warranty conditions, or long-term costs. This creates information asymmetry, where sellers know more than buyers. In such situations, consumers may use brand reputation, reviews, personal experience, or recommendations from friends to reduce uncertainty.

The cost of searching for information also matters. Searching for a cheaper phone contract takes time and effort. Comparing insurance plans may be difficult because terms are complex. This can lead to inertia: consumers remain with current providers even when better deals exist. Firms know this and may design products with complicated fee structures or automatic renewals. ECN1023 highlights that consumer choice is shaped not only by price, but by the effort required to understand the choice.

Consumer preferences: beyond price and quality

Price and quality are important, but consumer preferences often include many other factors:

• brand loyalty,
• convenience,
• time savings,
• status and identity,
• ethical concerns,
• safety and trust,
• peer influence.

A consumer may choose a more expensive product because it signals status. Another may choose a local brand because it aligns with identity or community support. A family may pay more for a closer store because transport savings offset the higher item price. Students often choose data bundles, food outlets, or transport options based on time pressure rather than purely on price.

A practical consumer decision framework

A useful exam-ready framework for consumer decision making is:

1. Identify the goal
   What need is being satisfied: survival, convenience, status, health, saving, or enjoyment?

2. List constraints
   Income, time, information, transport, family responsibilities, risk tolerance.

3. Compare alternatives
   Consider price, quality, convenience, and long-term consequences.

4. Evaluate trade-offs
   What is sacrificed if one option is chosen?

5. Choose under uncertainty
   Make the best available choice based on current information.

6. Review the outcome
   Was the decision satisfactory? Would a different decision be better next time?

This framework is useful because it captures both rational and behavioural elements. It recognises that consumers rarely maximise perfectly, but they do engage in goal-directed choice.

Consumer welfare and market outcomes

Consumer decisions influence market demand, which in turn affects firms, prices, and output. When consumers shift toward healthier products, firms respond by changing product lines. When consumers prefer lower prices, firms may compete more aggressively. When consumers are brand loyal, firms can charge premium prices. Thus, consumer behaviour shapes market structure as much as market structure shapes consumer behaviour.

4. Risk, Uncertainty, Time, and Intertemporal Choice

Many of the most important decisions in economics involve the future. People decide whether to save or spend, invest or wait, insure or self-fund, work now or study for later, and take risks or avoid them. ECN1023 pays close attention to these choices because real life is full of uncertainty and time trade-offs. Behavioural economics is especially useful here because future outcomes are difficult to evaluate, and people often overweight immediate consequences.

Risk versus uncertainty

Risk refers to situations where the probabilities of outcomes are known or can be estimated. Uncertainty refers to situations where probabilities are unknown or highly ambiguous. A game with clear odds involves risk. A new business opportunity with unclear market demand involves uncertainty. Many life decisions fall somewhere between the two.

People differ in their risk preferences:

• risk-averse individuals prefer certainty to a gamble with the same expected value,
• risk-neutral individuals care mainly about expected value,
• risk-seeking individuals prefer gambles in some situations.

Most people are risk-averse when it comes to losses of money, health, or security. This helps explain why insurance exists. Households pay premiums to reduce exposure to catastrophic losses. Similarly, firms may hedge exchange-rate risk, commodity risk, or interest-rate risk. The willingness to pay for protection reflects the value of certainty.

Expected utility and decision making under risk

The standard model of choice under risk is expected utility theory. A person evaluates each possible outcome by multiplying its utility by its probability and then summing across outcomes. The option with the highest expected utility is chosen. This model is elegant and useful, but actual behaviour often deviates from it.

People do not always assess probabilities accurately. They may overreact to rare but dramatic events. They may ignore small probabilities or exaggerate them. They also tend to value gains and losses asymmetrically. For example, the chance of winning a modest prize may motivate a lottery purchase, even though the expected monetary return is negative. Conversely, the chance of a small but embarrassing loss may strongly deter action.

Prospect theory and loss aversion

Prospect theory offers a more realistic account of choice under risk. It suggests that people evaluate outcomes relative to a reference point, not in absolute terms. Gains and losses are felt differently: losses loom larger than equivalent gains. This is loss aversion. If a person loses R100, the pain may be greater than the pleasure from gaining R100.

This helps explain common behaviour:

• reluctance to sell assets at a loss,
• overreaction to recent losses,
• preference for avoiding losses over pursuing gains,
• strong response to price increases even when small.

Loss aversion has major implications for pricing, saving, investing, and policy. A household may resist switching to a cheaper but unfamiliar product because the potential loss of quality feels more salient than the possible gain in savings. A student may avoid attempting a difficult question for fear of losing marks, even though some attempt could improve the outcome.

Time preference and discounting

Intertemporal choice concerns decisions across time. People often prefer immediate rewards over delayed rewards, even when waiting would produce greater total benefit. This is captured by discounting, the tendency to value future outcomes less than present ones. The standard model assumes a constant discount rate, but behavioural economics shows that people often display present bias: they heavily favour immediate gratification over future benefit.

Present bias explains procrastination, under-saving, poor health behaviour, and impulsive spending. A student may plan to study tomorrow, but when tomorrow arrives, the desire for rest is again stronger than the future benefit of preparation. A worker may intend to save monthly, but by month-end the temptation to spend dominates. A consumer may buy on credit because the pain of payment feels delayed.

Saving, borrowing, and self-control

Saving and borrowing are not only financial decisions; they are also self-control strategies. People use commitment devices to reduce temptation. Examples include:

• automatic deductions into savings,
• fixed deposits with penalties for withdrawal,
• budgeting apps,
• separate accounts for different goals,
• family agreements about expenditure.

These tools recognise that self-control is limited. Rather than expecting people to rely on willpower alone, they create structures that make the preferred action easier. This is one reason behavioural economics is so useful in personal finance and policy design.

Insurance and precautionary behaviour

Insurance protects against losses that are costly and unpredictable. The demand for insurance reflects both risk aversion and fear of extreme outcomes. Households insure homes, cars, health, and life because a major adverse event could be financially devastating. But insurance behaviour is not purely mathematical. People may underinsure because premiums feel like a loss, or overinsure certain risks because they are vivid and emotionally salient.

Precautionary behaviour also matters. A consumer may choose a more reliable appliance over a cheaper one to avoid future repair costs. A commuter may pay more for a safer route. A firm may keep extra inventory as a buffer against supply disruptions. These decisions show that economic behaviour is shaped by expected future vulnerability, not just present price.

Why time and risk are central to decision making

Risk and time connect many parts of the module. Investment, education, health, business strategy, and policy all involve future consequences. Economic behaviour cannot be understood properly without acknowledging that people are uncertain about the future and impatient about the present. This is why the study of decision making must go beyond static choice and include dynamic trade-offs, psychological discounting, and risk attitudes.

5. Incentives, Social Influence, and Applications in South African Contexts

Economic behaviour does not take place in isolation. People respond to incentives, but they also respond to family expectations, peer pressure, institutional rules, and social norms. In South Africa, these influences interact with inequality, unemployment, transportation constraints, and high living costs. ECN1023 is especially valuable because it allows students to analyse behaviour in realistic settings rather than abstract textbook environments.

Incentives in firms and organisations

Firms use incentives to shape employee behaviour. Wages, bonuses, promotions, recognition, and training opportunities all influence effort and loyalty. A simple payment structure can have complex effects. If workers are paid by output, productivity may rise, but quality may fall. If workers are paid fixed salaries, effort may be stable, but incentives to innovate may weaken. Good incentive design balances productivity, quality, fairness, and morale.

Managerial decisions also face behavioural challenges. Leaders may suffer from overconfidence, groupthink, and optimism bias. Teams may delay difficult decisions to avoid conflict. Firms may continue failing projects because of sunk cost fallacy, where past irrecoverable expenditure is wrongly allowed to influence current choices. Economically, sunk costs should be ignored because they cannot be recovered; only future costs and benefits should matter. Behaviourally, however, people often feel committed to what they have already spent.

Social norms and conformity

Social norms are informal rules about what is acceptable or expected in a group. They can be powerful drivers of behaviour. People may save money, study harder, or avoid waste because these actions are socially valued. They may also overspend, borrow irresponsibly, or engage in conspicuous consumption because of social pressure.

Conformity affects:

• clothing and consumption choices,
• gifts and family obligations,
• borrowing and lending behaviour,
• workplace effort,
• voting and civic participation.

A consumer may buy a particular phone because it is popular among peers. A family may hold an expensive celebration because social expectations make a modest event feel inadequate. A student may spend on appearances to fit in, even when money is tight. These decisions are not “irrational” in a simple sense; they reflect the utility people derive from belonging and status.

Institutions and decision environments

Institutions shape behaviour by defining rules, enforcement, and default options. Strong institutions reduce uncertainty and improve decision quality. Examples include:

• transparent pricing,
• reliable contract enforcement,
• consumer protection,
• clear academic rules,
• pension systems with automatic enrolment,
• digital payment systems with secure authentication.

When institutions are weak or confusing, decision costs rise. People may avoid formal financial products because they distrust providers. They may rely on informal credit if formal credit is inaccessible. They may make choices based on habit rather than comparison because comparison is difficult. Thus, institutions are not separate from behaviour; they structure behaviour.

South African examples of decision making

South African economic behaviour is shaped by specific realities:

• high unemployment increases risk aversion and makes job search decisions critical,
• transport costs affect where people live, work, shop, and study,
• income inequality influences consumption patterns and aspirations,
• electricity reliability affects business planning and household routines,
• debt pressure affects spending, saving, and mental well-being.

For example, a student commuting long distances may value time more than money when deciding whether to take a quicker but more expensive transport option. A household facing load-shedding may purchase alternative energy devices even if the upfront cost is high, because the long-term convenience is valuable. A small business may keep cash reserves because future revenue is uncertain. These examples show how context changes the meaning of “rational” choice.

Policy applications of behavioural economics

Policy makers increasingly use behavioural insights to improve outcomes. Instead of relying only on taxes and subsidies, they use:

• defaults to guide choices,
• reminders to improve compliance,
• simplification to reduce confusion,
• framing to encourage healthy or financially sound behaviour,
• commitment mechanisms to support saving and adherence.

In education, reminders and structured deadlines can improve submission rates. In health, clear information and simplified forms can increase uptake of services. In finance, auto-enrolment and easy savings options can improve participation. The key insight is that small changes in decision design can produce large behaviour changes because people are sensitive to effort, timing, and presentation.

Exam-ready conclusion on behaviour and decision making

Economic behaviour is the study of how people choose under scarcity, constraint, uncertainty, and influence. The standard model of rational choice provides a necessary baseline, but behavioural economics reveals why actual choices often diverge from it. People use heuristics, face limited attention, react to framing, and struggle with self-control. Their decisions are shaped by risk, time, social norms, and institutions. For ECN1023, the strongest answers are those that combine theory with realistic examples, explain both incentives and psychology, and show how economic outcomes emerge from human decision making rather than from perfect calculation alone.

High-yield exam summary table

Core concept	Meaning	Why it matters
Scarcity	Limited resources versus unlimited wants	Forces choice
Opportunity cost	Best alternative forgone	Central to rational decision making
Utility	Satisfaction from choices	Explains preferences
Bounded rationality	Decisions made with limited information and capacity	Realistic model of behaviour
Heuristics	Mental shortcuts	Fast but biased decisions
Loss aversion	Losses hurt more than equal gains please	Explains caution and inertia
Present bias	Strong preference for immediate rewards	Causes procrastination and under-saving
Risk aversion	Preference for certainty	Explains insurance and cautious behaviour
Social norms	Informal rules and expectations	Shape consumption and compliance
Incentives	Rewards and penalties affecting choices	Drive behaviour in markets and policy

Exam strategy for ECN1023

To answer exam questions well, structure responses clearly:

1. define the concept,
2. explain the theory,
3. identify the behavioural insight,
4. apply it to a practical example,
5. conclude with why it matters for policy or decision making.

When writing longer answers, show the difference between the standard economic model and behavioural economics. Examiners usually reward students who can move from abstract theory to concrete application. Strong answers also distinguish between similar concepts such as risk and uncertainty, rationality and bounded rationality, or incentives and social norms. In this module, precision of language is as important as depth of understanding.