"So if those are the characteristics of an irrational consumer, what would be the characteristics of a rational consumer?"
RATIONAL CONSUMER CHOICE
--ASSUMPTIONS OF RATIONALITY--
--1️⃣ CONSUMER RATIONALITY--
"Are you are capable of making a choice?"
If you said "Yes" then you are being rational,
The COMPLETENESS ASSUMPTION states that a rational consumer should always be able to RANK THEIR PREFERENCES and say,
“I prefer A over B,” “I prefer B over A,” or “I’m indifferent.”
"Why is this assumption necessary?" Well, if someone can’t decide—e.g., “I have no idea if I prefer going to the gym or staying home,” or “I can’t compare apples to oranges at all”—then their preference system is incomplete, meaning they cannot fully construct a rational demand pattern because without clear preferences, you cannot optimise satisfaction (utility)—which is the whole point of rational choice theory.
Real-world example: "I always prefer Coke to Pepsi"
"Are you consistent with your choices?"
The TRANSIVITY ASSUMPTION states that a rational consumer should always be able to KEEP THEIR PREFERENCES CONSISTENT and say, "If I prefer A over B, and B over C — I should logically prefer A over C."
"Why is this assumption necessary?" Well, how could a reliable demand curve exist if consumers kept changing their minds—preferring A over B one moment, B over C the next, and suddenly C over A?”
Real-world example: "I always prefer Coke to Pepsi, and I'd rather have a Pepsi over a Sprite, so I definitely prefer Coke to Sprite."
"Do you believe more is always better?"
The NON-SATIATION ASSUMPTION states that a rational consumer should always be able to say, "I prefer more of a good rather than less."
"Why is this assumption necessary?" Well, how could a demand curve slope downwards if consumers actually preferred less of a product rather than more of it?”
Real-world example: "If the price of Coke falls, I would prefer to buy more"
--Use the markscheme below to construct both 10-mark answers--
"In a perfect world, the price I am willing to pay for something is perfectly informed, as I am fully aware of the full costs and full benefits that it will give me, so I can make a really good judgement on its value and pay accordingly." "Sound realistic?"
--2️⃣ PERFECT INFORMATION--
In order to construct your individual demand curve it is assumed that you are able to base the price you are wilingness to pay for each unit, on your 'well-informed' idea of the benefit ('utility') that you will recieve from consuming it right!
"I know what a coke tastes like, I know what the price of alternatives are, I know the basic health implicatons of drinking it, and I am not influenced by any adverts, therefore, i'm happy to pay $10 for my first cup and so on..."
Therefore, for this to be true you would need to have PERFECT KNOWLEDGE about the benefits and satisfaction that they will receive from consuming the good or service and hence THE PRICE THEY CONSUMERS ARE PREPARED TO PAY IS FULLY REFLECTIVE OF THEIR PRECISE EXPECTED STREAM OF BENEFITS, WHICH THEY ALWAYS SEEK TO MAXIMISE.
--3️⃣ UTILITY MAXIMISATION--
“When I consume a good or service, I not only know the full costs and the full benefits, but also know exactly when my satisfaction is maximised, so I always buy the precise quantity that makes me the happiest."
In addition to being PERFECTLY INFORMED rational individuals will always SEEK TO MAXIMISE THEIR OWN 'SELFISH' SATISFACTION ('UTILITY'), and consume up to the point where their marginal benefit = marginal cost.
Is this realistic? If you’re buying for someone else, how do you know their level of benefit accurately? Do people never overeat at a buffet, drink more than they should, or buy extra things they don’t really need? In theory, the demand curve is perfectly accurate in every way. In reality… maybe not so much.
--REALITY OF RATIONLITY--
"When you see two makeup items, one with Korean and one with Russian, which do you buy?" "Why?"
"We regularly take mental shortcuts based on experience and common sense (these are called 'RULES OF THUMB' or heuristics') because we like to 'speed up' and 'simplify' complicated decisions."
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--TASK--
"Look at the infographic above and explain the rule-of-thumb that this customer is using when deciding to buy goods. Then decide whether choosing a product that contains the word "international" over others would be considered a rule of thumb?'
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'Now the rule-of thumb itself is the "tool", but when it is used extensively and results in outcomes that would go against the rational outcome, say for example, due to limited knowledge, we say that there has been some sort of cognitive bias impacting the outcome. There are many biases, and here are just a few for the IBDP.
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--TASK--
"Look at the infographic above and explain the bias that this customer is using when deciding to buy goods. Then explain how your decision to study IBDP, could be considered 'irrational.'
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"BOUNDED SELF-CONTROL is the idea that people have a limited capacity to resist temptations and delay gratification, leading them to make decisions that prioritize immediate desires over long-term benefits. This concept explains why people might overeat, overspend, or continue gambling even when they know it's not in their best interest, as their good intentions are overcome by the power of impulse and short-term rewards."
--ADD 2025 P3 QUESTION: QUESTION...GYM MEMBERSHIP PEOPLE STRUGGLE TO MAINTYAIN SELF CIONTROL, EATING UNHELTHY TO GET A SHORT TERM HIT RATHEWR THAN THINK OF LONG TERM HEALTH GAINS BINGE EATING, PRICRASTINATION, ADDICTION
"In my opinion, buying an iPhone is like choosing a restaurant just because the sign outside looks fancy. You don’t check the menu, read the reviews, or ask how good the food actually is—you just assume that if the logo is shiny and the name is popular, it must be good. In reality, the no-brand alternative might last longer and have more functionality at half the price, but you’ll never know because your brain took the irrational shortcut."
"BOUNDED RATIONALITY refers to how in reality a person is either not able or not willing to seek information that would help them understand the true value and worth of a decision. This could be due to lack of access to the information, lack of mental capacity to comprehend it or simply lack of time available to gather, learn and process it."
"I'm not swimming at the beach because of that dramatic shark attack video I just saw on YouTube. Never mind that shark attacks are insanely rare—I remember that one scary clip so clearly that it feels like it happens all the time."
"AVAILABILITY BIAS refers to how we often BASE OUR DECISION-MAKING on RECENT INFORMATION or IMAGES rather than look at a choice in its entirety."
"EXPLAIN USING THE CONCEPT OF 'AVAILABILITY BIAS' HOW THE FOLLOWING THREE IMAGES INFLUENCE DECISION-MAKING REGARDING THE DEMAND FOR SWIMMING TRUNKS IN SPAIN, PLANE TICKETS, AND LOTTERY TICKETS."
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"How do you feel about deciding to study the IBDP economics course after hearing these two statements?"
"Unfortunately, 20% of all IBDP economics students fail!"
or
"A whopping 80% of IBDP econ students pass, whoop, whoop!"
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"That's right, the way the statement is 'framed', can 'bias' or 'prejudice' your desire, and utimately, your demand for the good or service will be sub-optimal."
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"FRAMING BIAS refers to how our decision-making is highly influenced by the PRESENTATION of the choice."
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"For example which of the following would you choose?"
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Watch this clip and explain how it illustrates 'FRAMING BIAS'.
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"Do you think she overpaid?"
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"Duh yes she overpaid, it's a classic sales technique, the $100 price is set high and the customer starts using it as a reference point when bargaining, without ever really appreciating the true value of the item and how much she should be willing to pay, instead focusing on getting a lower price than the 'anchor price'."
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"ANCHORING BIAS is a cognitive bias whereby an individual's DECISIONS ARE INFLUENCED BY A PARTICULAR REFERENCE POINT or 'ANCHOR'."
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"BOUNDED SELFISHNESS refers to a cognitive bias that counters the assumption that rational consumers will, out of self-interest, always choose the least cost/best value option, stating that in reality their level of 'selfishness' is bounded by their human desire for social approval, fairness, and moral purity, which often causes them to act against their own financial best interest."
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--Use the markscheme below to construct both 15-mark answers--
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"MY APPLE DUO STORY"
Highlight the sections you think illustrate each of the seven biases covered so far:
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"Alex had been saving for months to buy a new phone. One afternoon he saw an advert for the new Apple Duo, a package containing the latest phone and smartwatch. The advert immediately caught his attention because it displayed a large crossed-out price of $2,500, followed by a special offer price of $1,999. Although Alex had never thought about how much the Apple Duo should actually cost, the original figure stuck in his mind and made the new price seem like an incredible bargain."
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"Later that day, Alex visited another retailer's website. Interestingly, the package cost exactly the same amount, but the promotion was worded differently. Instead of focusing on the total price, it stated, "Own the Apple Duo for less than $55 per week." Suddenly the purchase felt much more affordable. Alex barely thought about the total amount he would eventually pay and focused instead on the smaller weekly figure."
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"As he continued researching, Alex remembered seeing countless social media posts about the Apple Duo. Several YouTubers he followed had praised its features, and many of his friends had been talking about it all week. Because these examples came to mind so easily, Alex began to assume that the Apple Duo must be the best device on the market. He rarely noticed the reviews discussing competing products because the positive stories about Apple were much easier for him to recall."
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"Alex knew there were many alternatives available. Several other brands offered similar phones for lower prices, and there were hundreds of reviews comparing different models. However, after reading a few articles and watching several comparison videos, he became overwhelmed by the amount of information. There were simply too many specifications, prices, contracts, and warranty options to compare. Eventually he thought, "I've spent enough time on this already. I'll just choose something that seems good enough."
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"As he walked past an Apple Store the next day, he noticed a large sign describing the Apple Duo as the company's newest flagship product. Without carrying out any further research, Alex reassured himself by thinking, "Apple products are always high quality. Whenever I buy Apple, I never regret it." This simple rule made his decision feel easy and saved him the trouble of analysing all the remaining options."
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"Alex had originally planned to wait another three months so he could pay for the device in full. He knew that delaying the purchase would leave him with more savings and avoid any extra costs. However, the salesperson explained that he could take the Apple Duo home immediately by signing up for a payment plan. Alex imagined showing the new device to his friends at school the next day. Even though he knew waiting would probably be the wiser financial choice, the excitement of owning it immediately was too difficult to resist."
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"Just before paying, the salesperson showed him a premium protective case that cost far more than similar cases available online. The salesperson explained that part of the purchase price would be donated to a charity supporting children's education. Alex realised that a cheaper case would leave him with more money, but he liked the idea that some of the money would help others. He purchased the expensive case anyway, feeling pleased that his choice might benefit someone else."
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"When Alex arrived home with his new Apple Duo, he believed he had made a carefully considered decision. Yet if someone examined his decision-making process closely, they might notice that he had relied on the first price he saw, been influenced by the way the offer was presented, focused heavily on examples that were easy to remember, stopped searching when information became overwhelming, depended on a simple shortcut based on past experience, given in to the temptation of immediate satisfaction, and even sacrificed some personal financial benefit in order to help others."
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"For an economist, Alex's purchase raises an interesting question: did he choose the option that truly maximised his benefit at the lowest possible cost, or was his judgement influenced by predictable patterns in human behaviour?"
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"Highlight the sections they think illustrate each of the seven concepts and then write the concept name plus a one-sentence definition in the margin. This works well as a behavioural economics starter activity before introducing the theory."
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"Now that you have correctly identofied the biases, choose three and explain how the story illustrates this bias: For example:
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"The story illustrates the impact of anchoring bias as Alex was influenced by the initial price of $2,500, which became a reference point and made $1,999 appear to be good value, it also illustrates the impact of...."
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"CHOICE ARCHITECTURE refers to the way/method in which choices are presented and structured to consumers in order to influence their decision-making while maintaining freedom of choice."
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"Can you think of the reason why a sticker of a fly is often stuck in a urinal?" "What type of behaviour is this trying to impact, and why?" "How is this related to choice?" "Does it involve being told what to do?"
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"The sticker is stuck in the urinal in an attempt to 'nudge' (persuade) the user to 'take better aim', which should reduce spillage and the associated cleaning costs. There is no one forcing the user to hit it (it's not mandated by law) nor rewarding them; the choice is completely optional; however, it undoubtedly impacts decision-making."
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--TASK--
"Explain how this is an example of choice architecture."
"Explain how choice architecture can solve this problem."
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"I know let's set the default printing settings to 'portrait', 'two-sided', and 'black & white'."
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"Hang on a minute!!!!"
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⚠️"Do you think this is manipulative behaviour?", "How does it make you feel that someone else is trying to alter your decision-making for you?" "Will you do the opposite, to 'rebel' against your manipulators", "Will the choice architecture have a 'boomerang effect'?"
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"Look at this image, below and describe what is happening."
"What do you think will happen when they realise?"
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"As a final note, this alternative rebellious behaviour will likely lead to even more wastage so it clearly backfired."
DEFAULT CHOICES refers to a type of choice architecture in which a choice has already been chosen 'by default', and the user still has the 'freedom of choice' to switch, but due to
FREEDOM TO CHOOSE ✅ Yes, people can change the default
ABILITY TO 'NOT CHOOSE' ✅ Yes, inaction means you choose the default
"The option that a consumer 'selects' if he/she DOES NOTHING."
"Does this work?" Yes, as when it comes to thinking, PEOPLE ARE LAZY. Studies have shown that people rarely change the default settings. Microsoft found that 95% of people kept all default settings, even for critical features like autosave.
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REAL-WORLD EXAMPLE: OPT-OUT ORGAN DONATION SYSTEM IN THE UK.
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"Often students view uniforms and restrictive-ish dress codes as unnecessary and just a way for the school to 'restrict' your freedoms, but in fact these restrictive choices have a real psychological impact that actually helps your focus and study, but how?"
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RESTRICTED CHOICES refers to...
"The options that a consumer “selects” are limited."
"Does this work?" Yes, in this case it's about forcing customers to make a decision, rather than be overwhelmed with choice and walk away ('The Paradox of Choice')
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"When the government installed strict 'mask-wearing' rules for living in HK, such as access to the MRT, why did they call them 'mask mandates'?" "What was the option if you didn't comply?"
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"The option is 'go without'."
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MANDATED CHOICE refers to a situation when people are required to make a decision, rather than being allowed to ignore or skip the choice. It effectively removes the option of no action, unless you want to end up with nothing. e.g NO INSURANCE = NO CAR.
FREEDOM TO CHOOSE ✅ Yes, you can still change
ABILITY TO 'NOT CHOOSE' ✅ Yes, inaction means you choose the default
"You have the option to not choose, but by doing so you end up with consequences."
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"When you see these footprints on the escalator, what type of behaviour is it trying to impact? Is it beneficial to you?"
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"When you see this on your towel dispenser, what type of behaviour is it trying to impact? Is it beneficial to you?"
A 'NUDGE' refers to a way of INFLUENCING CONSUMER'S CHOICES with the aim of IMPROVING THE INDIVIDUAL'S or SOCIETY'S WELFARE WITHOUT using the following:
1) FINANCIAL REWARDS for compliance.
2) SANCTIONS for non-compliance.
3) LIMITING CHOICES.
"Why do some supermarkets put sugary treats at the checkout?, Who benefits?"
"When the online store says, 'Only 2 left, hurry!'" Is it always beneficial to you?"
"When you want to cancel your gym membership, do you think it's super easy or difficult?"
A 'SLUDGE' refers to a way of INFLUENCING CONSUMER'S CHOICES with the aim of MAKING IT INTENTIONALLY HARDER FOR PEOPLE TO MAKE CHOICES THAT ARE IN THEIR OR SOCIETY'S BEST INTERESTS WITHOUT using the following:
1) FINANCIAL REWARDS for compliance.
2) SANCTIONS for non-compliance.
3) LIMITING CHOICES.
READ EACH OF THE ARTICLES BELOW and write a brief explanation of how 'NUDGE-THEORY' has been used in each scenario to manipulate behavior.
Nudge theory in negotiations—Gale, A. (2020). Nudge theory in negotiations. Management Today. www.managementtoday.co.uk/nudge-theory-negotiations/food-for-thought/article/1689854/.
Group 2: Nudge theory in workplaces—Agarwal, M. (2020). ‘Nudging’ to create a better workplace: Nudge theory in practice. Inc42. https://inc42.com/resources/nudging-to-create-a-better-workplace-nudge-theory-in-practice/.
Group 3: Nudge theory as a public policy tool—Lokeshwarri, S. K. (2020). Is ‘nudge’ a desirable public policy tool? The Hindu Business Line. https://www.thehindubusinessline.com/opinion/columns/is-nudge-a-desirable-public-policy-tool/article33126549.ece.
Group 4: Nudge theory to prevent vaccine hesitancy during Covid-19—Jain, S. (2020). Vaccine to vaccination: Using nudge theory to prevent vaccine hesitancy. Observer Research Foundation. www.orfonline.org/expert-speak/vaccine-to-vaccination-using-nudge-theory-to-prevent-vaccine-hesitancy/.
To what extent can manipulation and deception ever be good for individuals and societies?”
Should governments assume they know what’s best for us?
Is it okay for companies to use nudges to increase profits?
How can we judge whether a nudge is ethical or a sludge?
--RATIONAL PRODUCER--
PROFIT MAXIMISATION:- Standard economic theory of the firm assumes that RATIONAL FIRMS are solely geared towards maximising their profits, and that they will be willing to produce up to the last unit of a foot that yields even the smallest % profit (MC=MR). Do you think this is really the case? Do you think your school's main goal is profit maximisation?
CORPORATE SOCIAL RESPONSIBILITY (CSR):- The self-interested behaviour of firms often leads to negative consequences for society. It is often the case that the well-being of firms is not consistent with the welfare of society. A prime example is the self-interested firm that pollutes the environment. In addition, firms can engage in actions that most consumers would consider to be ethically unacceptable, such as the practice in many developing countries of employing children who are extremely poorly paid and forced to work long hours, or employing labour that is forced to work under unhealthy or dangerous conditions. However, many firms are increasingly recognising that the pursuit of self-interest need not necessarily conflict with ethical and environmentally responsible behaviour. A negative image of the firm held by workers and customers (buyers of the product) can cut deeply into the firm’s revenues and profits by lowering worker productivity and the firm’s sales. Further, socially irresponsible firm behaviour may lead to government regulation of the firm intended to minimise the negative consequences of the firm’s actions for society, whereas socially responsible behaviour could instead result in avoidance of government regulation. Therefore, firms face strong incentives to display corporate social responsibility by engaging in socially beneficial activities such as art and athletics sponsorships, donations to charities. Many of these practices are the result of increased consumer awareness of social and environmental issues, growing consumer concern over ethical and environmental aspects of business practices, and even consumer activism that results in boycotts of offending firms. One indication of the influence and concern of consumers is the rapidly growing interest in investments in companies (through stock markets) that meet certain social, ethical and ecological criteria. Economists used to think that ethical and environmentally responsible behaviour of firms would reduce their profits. This was based on considering only the cost aspect of profits; for example, firms using cheap child labour face lower costs, and hence will make higher profits than firms avoiding such practices. Yet profits depend not only on costs, but also on revenues. If consumers avoid buying the products responsibility of offending firms, revenues will decline and profits will go down in spite of the lower costs. The same arguments also apply to firms that may be pursuing some strategy other than profit maximisation, such as revenue maximisation. SUSTAINABLE INDEX LEGO, COKE-COLA, SAMSUNG, STARBUCKS, APPLE, MCDONALDS
SATISFICING:- All of the above objectives assume that the firm tries to maximise some variable, whether it is profit, revenue, growth or managerial utility. H. Simon, a Nobel Prize-winning economist, has argued that the large modern enterprise cannot be looked upon as a single entity with a single maximising objective; instead it is composed of many separate groups within the firm, each with its own objectives which may overlap or may conflict. This multiplicity of objectives does not allow the firm to pursue any kind of maximising behaviour. Firms therefore try to establish processes through which they can make compromises and reconcile conflicts to arrive at agreements, the result of which is the pursuit of many objectives that are placed in a hierarchy. This behaviour was termed satisficing by Simon, referring to the idea that firms try to achieve satisfactory rather than optimal or ‘best’ results.
GROWTH MAXIMISATION:- firms may be interested in maximising their growth rather than their profits as the larger they grow the more economies of scale they can achieve and the lower it's average costs. Also as a firm grows it can diversify into the production of different products and markets which reduces its dependence on a single product or market, and finally with a larger share, it can yield greater market power and will have more control over the prices it can charge.
EDULASTIC
RULE OF THUMB BIAS: The habit of having two working phones was not a rule-based on anything other than habit, and a personal preference, in other words a rational consumer would not see any sense in buying two phones rather than one.
BOUNDED SELF-CONTROL: The fact that I was unable to control myself and bought a third phone shows how irrational I am as a consumer as it is very unlikely that the cost of all three phones reflected my total utility.
BOUNDED RATIONALITY: I lacked both the time and the mental capacity to do thorough research on the true worth of the phone and instead just settled for the opinion of a couple of review sites.
AVAILABILITY BIAS: I dismissed the i-phone, due to the news that one had recently exploded, despite the millions of i-phones that haven't exploded.
FRAMING BIAS: I was influenced by the actual design of the Samsung shop, which 'framed' the brand as very hi-tech and reliable.
ANCHOURING: The $2000 price tag of the phone influenced my idea about whether the 10% discount was actually a good or bad deal, I immediately ignored whether the phone was ever worth $2000 in the first place.
The answer is 'Yes', some customers make a conscious mental decision to buy goods and services that appear more 'global' or 'internationally recognised' in the belief that it is of a higher 'quality' avoiding the need to research."
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"Do you only buy 'made in the US' products over 'made in China'?