Ejercicio. Deducción de la demanda individual de consumo, a
partir del cambio en el precio de uno de los bienes y el consecuente cambio de
la canasta óptima
Con los siguientes datos:
Función de utilidad tipo Cobb Douglas de los gansitos y refrescos: U(g,r) = 4g 3/4r 1/4
La renta del consumidor m= 200; y el precio individual de
los gansitos es Pg= 4 y el precio individual de los refrescos es Pr=8. Por lo tanto 200 = 8r + 4g (renta = gasto)
a) plantea la función objetivo a maximizar
b) obtén las condiciones de primer orden
c) Calcula el valor de g (cantidad de gansitos) y luego el
valor de r (cantidad de refrescos)a
través de la ecuación de restricción presupuestaría
d) demuestra que con la elección óptima obtenida del inciso anterior
se cumple con la condición de que en el punto de elección óptima la UMGr /UMGg = - (Pr/Pg); UMG es la utilidad
marginal, de los gansitos (g) o de los refrescos (r)
e) obtén el valor de la función de utilidad
f) realiza los mismos procedimientos de los incisos
anteriores cuando, con todo lo demás constante, el precio de los refrescos es
dePr´= 4 y luego de Pr´´=2
g) en un gráfico traza los movimientos de la línea de restricción
presupuestaria con las canastas óptimas según el precio de los refrescos y
traza tres curvas de indiferencia que sean tangentes a cada línea de
restricción presupuestaria en cada elección óptima. (los refrescos en el eje de las abscisas y los gansitos en el eje de las ordenadas)
h) con una gráfica
debajo de la anterior delinea la curva de demanda individual de los refrescos
cuando el precio pasa de Pr = 8; Pr´=4 y Pr´´ = 2.
The insight that will save you from being manipulated.
By David Berreby Illustration by Michael Meister
February 26, 2015
Imagine that (for some reason
involving cultural tradition, family pressure, or a shotgun) you
suddenly have to get married. Fortunately, there are two candidates. One
is charming and a lion in bed but an idiot about money. The other has a
reliable income and fantastic financial sense but is, on the other
fronts, kind of meh. Which would you choose?
Sound like six of
one, half-dozen of the other? Many would say so. But that can change
when a third person is added to the mix. Suppose candidate number three
has a meager income and isn’t as financially astute as choice number
two. For many people, what was once a hard choice becomes easy: They’ll
pick the better moneybags, forgetting about the candidate with sex
appeal. On the other hand, if the third wheel is a schlumpier version of
attractive number one, then it’s the sexier choice that wins in a
landslide. This is known as the “decoy effect”—whoever gets an inferior
competitor becomes more highly valued.
The decoy effect is just
one example of people being swayed by what mainstream economists have
traditionally considered irrelevant noise. After all, their community
has, for a century or so, taught that the value you place on a thing
arises from its intrinsic properties combined with your needs and
desires. It is only recently that economics has reconciled with human
psychology. The result is the booming field of behavioral economics,
pioneered by Daniel Kahneman, a psychologist at Princeton University,
and his longtime research partner, the late Amos Tversky, who was at
Stanford University.
It’s all about leveraging the unconscious factors that drive 95 percent of consumer decision-making.
It
has created a large and growing list of ways that humans diverge from
economic rationality. Researchers have found that all sorts of logically
inconsequential circumstances—rain, sexual arousal (induced and
assessed by experimenters with Saran-wrapped laptops), or just the
number “67” popping up in conversation—can alter the value we assign to
things. For example, with “priming effects,” irrelevant or unconsciously
processed information prompts people to assign value by association
(seeing classrooms and lockers makes people slightly more likely to
support school funding). With “framing effects,” the way a choice is
presented affects people’s evaluation: Kahneman and Tversky famously
found that people prefer a disease-fighting policy that saves 400 out of
600 people to a policy that lets 200 people die, though logically the
two are the same. While mainstream economists are still wrestling with
these ideas, outside of academe there is little debate: The behaviorists
have won.
Yet for all their revolutionary impact, even as the behaviorists have overturned the notion that our information processing is economically rational, they still suggest that it should be
economically rational. When they describe human decision-making
processes that don’t conform to economic theory, they speak of
“mistakes”—what Kahneman often calls “systematic errors.” Only by
accepting that economic models of rationality lead to “correct”
decisions, can you say that human thought-processes lead to “wrong”
ones.
But what if the economists—both old-school and
behavioral—are wrong? What if our illogical and economically erroneous
thinking processes often lead to the best possible outcome? Perhaps our
departures from economic orthodoxy are a feature, not a bug. If so, we’d
need to throw out the assumption that our thinking is riddled with
mistakes. The practice of sly manipulation, based on the idea that the
affected party doesn’t or can’t know what’s going on, would need to be
replaced with a rather different, and better, goal: self knowledge. The behaviorist: Daniel Kahneman pioneered behavioral economics, together with the late Amos Tversky.Photo by Sean Gallup/Getty Images for Burda Media Nowadays, that fast-food company trying to get you to eat fries and the Health Department trying to get you not
to both use techniques drawn from behavioral economics—framing and
priming you to make certain choices. Welcome to the new era of “choice
architecture,” “behavioral marketing,” and “nudge.”
It’s guiding a
new approach to advertising and marketing based on a simplified version
of behavioral economics—which holds that people are inconsistent,
illogical, easily influenced, and seldom aware of why they choose what
they choose. “It’s all about leveraging the unconscious factors that
drive 95 percent of consumer decision-making, and the best way to do
that is through behavioral economics,” wrote Michele Fabrizi, president
of the advertising agency MARC USA, in a recent issue of Advertising Age.
Behavioral approaches are also infusing management. According to John
Balz, Chief Behavioral Officer of a software firm called Opower, as many
as 20 percent of Fortune 500 companies now have someone responsible for
bringing behavioral science perspectives to business decisions and
operations.
Governments are also jumping on the behavioral
science bandwagon. In fact, the massive interest in behavioral economics
shown by private enterprise has become an argument in favor of the
“choice architecture” now used by both governments and do-gooder
organizations. With companies working so hard to get you to eat potato
chips, drink beer, and spend all your money right now, goes the
argument, it’s the government’s duty to use similar techniques to get
you to make better choices. This approach, dubbed “Nudge” by economist
Richard Thaler and law professor Cass Sunstein in their 2008 book of
that title, marks an even bigger change for politics than for business.
Citizens of democracies are used to government telling them what they
should do, and offering carrots, or sticks, to get compliance. They
aren’t so used to government trying to change people’s behavior without
being noticed.
The premise of many nudge tactics—that people’s thinking processes are full of mistakes—may be wrong.
For
nudge policies to work, experts have to identify an undesirable
outcome, then figure out how to use our own decision-making “errors” to
“nudge” us toward a better choice. For example, Sunstein writes, “Many
people think about their future selves in the same way they think about
strangers, but if you show people pictures of what they’ll look like in
twenty years, they get a lot more interested in saving for retirement.”
In other words, helping people who make mistakes requires experts who
know “better.”
Today, nudge is truly a global phenomenon.
According to Mark Whitehead, a geographer at Aberystwyth University in
Wales, and his colleagues, nudge policies are in place in 136 of the
world’s 196 nations. And in 51 of those nations, including China, the
United States, Australia, and countries in West Africa, East Africa, and
Western Europe, the approach is being directed by a nationwide,
centralized authority. From 2009 to 2012, Sunstein himself was head of
the White House Office of Information and Regulatory Affairs, which
oversees all U.S. government regulations. The United Kingdom has a
“nudge squad” (Thaler is a consultant), as does the U.S. government.
This
is how a debate among psychologists and economists has come to have
cultural significance. A government that assumes people make mistakes
needs expert to describe the “correct” decisions, which doesn’t always
happen. That’s an odd position for a democratic government to be in,
argues the philosopher Mark D. White, a philosopher at the College of
Staten Island who is a skeptic of nudge tactics. “Yes, business does
it,” he says, “but here is the difference: Everybody knows
business tries to manipulate you. We don’t expect the government to
manipulate us. That’s not the role that most of us assign to our
government.” People who lost their retirement savings in the financial
crisis of 2008 might be forgiven for wishing they had not been nudged to
invest so much.
What’s more, the premise of many nudge tactics—that people’s thinking processes are full of mistakes—may be wrong. At
the heart of the notion that human decision-making is error-prone is
the conviction that aspects of choice should divide neatly into a
relevant signal (what does it cost? how much does it matter to me?) and
irrelevant noise (does the way it was presented sound hopeful or sad? Is
it sunny outside?). But defining what information is relevant isn’t as
obvious as it may sound.
What is “noise” in a one-off choice
(pick A or B) can be relevant information when an organism is repeatedly
chasing resources in changeable and uncertain conditions, notes Donald
Hantula, a psychology professor who directs the Decision Making
Laboratory at Temple University. If you read research that emphasizes
“mistakes,” he says, “one of the conclusions you would come to is that
human beings are just stupid. As a lifelong member of the species, I have a little bit of a problem with that.”
Susceptibility
to the “decoy effect” is just one of a number of “irrational” decision
strategies that have stood the test of evolutionary time, which suggests
these strategies have advantages. In fact, studies with all sorts of
animals have found they make the same economic “mistakes” as humans.
Even the slime mold—a collective of unicellular organisms that join
together to form a slug-like whole—is susceptible to the decoy effect.
Tanya Latty and Madeleine Beekman, biologists at the University of
Sydney, have shown that when faced with a choice between a rich
oatmeal-and-agar mix under bright lights (which interferes with their
cell biology) and a less nutritious mix in comfortable darkness, slime
molds showed no strong preference. They act a bit like diners comparing a
loud, unpleasant restaurant with great food to a nice, quiet place with
a blah menu—could go either way. (In fact, slime molds being what they
are, some headed in both directions at once.) But when the researchers
added a worse dark option (the equivalent of a quiet joint with really
bad food), the slime molds dropped the bright option and chose the
better of the two dark ones. “When you start to see the same fundamental
problems solved by all kind of species it begins to suggest there’s
some sort of common mechanism,” says Hantula.
Laurie Santos, a
professor of psychology and cognitive science at Yale University, has
found some mechanisms that might be shared primarily by primates. Like
the typical person—who prefers to start with a $10 bill and try to win a
second, rather than starting with two bills and risk losing
one—capuchins preferred to start with a grape and try for another,
rather than risk losing two grapes they already held. They were, in
behavioral jargon, “loss averse.” Santos suspects this trait might have
evolved because monkeys, like most primates, need to keep track of
social relationships. Mutually Beneficial: Snow monkeys grooming each other in a natural hot spring near Yudanaka, Japan. Shutterstock / David Evison Monkeys
track social relationships by grooming one another. If you’re a monkey
exchanging this favor with others, and another monkey does more for you
than you did for him, it’s a small gain for you, and not a problem. “But
if somebody failed to groom you as much as you did them
yesterday,” Santos says, “that’s a big problem and you should have a
mechanism to get upset about that.” In primates, loss aversion may be a
helpful rule-of-thumb rooted in monitoring of social tit-for-tat. “It’s
possible that what we’re seeing in the context of these classic
heuristics are actually strategies built for something else,” says
Santos. “That doesn’t mean they’re bad or errors.” As Gerd Gigerenzer,
Director at the Max Planck Institute for Human Development, in Germany,
puts it, a strategy may be “ecologically rational”—the most successful
method for solving real problems overall—even if it violates assumptions
about rational decision-making.
If
I am saving you from turning the wrong way when you are lost, what
difference does it make if you don’t know I am steering you?
Thinking
about humans as social animals casts a different light on some famous
framing effects often cited as examples of human information-processing
“error”: Why can’t we recognize that saving 400 people out of 600 is the
same as letting 200 people die? One good reason might be that even
though the cases are logically identical, they aren’t socially
identical—one choice is framed in a way that emphasizes death, and the
other, life. In many real-life situations, that difference is relevant
information. Even as we share some supposedly error-prone methods of
decision-making with very distant relatives like the slime mold, other
“mistakes” may reflect the particular needs of primates. In fact, some
of our mistakes may be peculiar to our species alone.
Santos, who
studies primates to understand the evolution of the human mind, notes
that monkeys—even our close cousins, chimpanzees—are not as attuned to
social cues, the consequence being that they act more like rational
agents. For example, in experiments with a simple puzzle—open this box,
take out a prize—Victoria Horner and Andrew Whiten showed both human
children and young chimpanzees how to solve the puzzle. In one set of
trials, the box’s transparent plastic sides were covered by black tape.
In the other, the tape was gone, making it obvious that several of the
experimenters’ steps were unnecessary. The chimps reacted to this by
skipping the useless steps. But 80 percent of the human children stuck
with the more complicated procedure. They were “over-imitating”—sticking
more closely to what a person showed them than necessary. Humans,
especially children, often make the “mistake” of over-imitating when
they learn new skills. While over-imitation is not always the most
efficient or rational way to solve a problem, it may be a way to pass on
crucial information—including custom, etiquette, tradition, and
ritual—that we need to be human.
Suppose,
though, there was a seat at the table for researchers who accept that
people depart from economic rationality, but don’t call that departure a
form of error. Would their model make a practical difference?
There
are signs that it could. Here is why: Policymakers who assume people
are constantly making mistakes must strive to correct “errors” by subtly
rearranging choices, but policymakers who don’t assume people
make mistakes can instead orient their efforts to bringing people’s
attention to their own mental processes. Once aware of these mental
processes, people can then do what they will. It’s a subtle but
important difference. The first approach nudges people toward a
pre-chosen goal; the second informs people about the workings of their
own minds, so they can better achieve whatever goals they desire.
Consider
this nudge-like strategy, designed by Hantula. About a year ago, he and
some colleagues devised a procedural change in the cafeteria of a
hospital. “If you ask people at 7:30 in the morning if they want a
healthy lunch or something less healthy, they’ll say ‘I choose a healthy
lunch’,” says Hantula. “The problem is, at about noon, when they walk
up to the cafeteria and the guy at the counter is flipping burgers, they
say, ‘I’ll take the burger!’ ” Hantula and his colleagues gave workers a
new option. “We were able to get the software that ran their cafeteria
and their billing system reprogrammed so that people could pre-order and
pay for their lunch at 7:30 in the morning.” By moving their “choice
point” from lunchtime to an hour when people preferred a healthier
lunch, a significant percentage of workers ended up eating healthier
food.
This might sound like a typical nudge. But it is subtly
different from those that seek to get people to exercise, invest in
retirement, or get medical check-ups without their noticing. In
Hantula’s study, the intervention isn’t covert. It calls attention to
the decision it’s attempting to influence. “If you approach it from the
perspective of ‘oh, these people are stupid, so let’s arrange things so
we use their stupidity against them,’ that’s one thing,” Hantula says.
“This is different. It’s not sneaky at all.” If your goal is to eat
healthier, here’s a way you can reach that goal.
To assume that
people make mistakes all the time is to assume that they needn’t be
aware that a government or business is trying to change their behavior.
After all, if I am saving you from turning the wrong way when you are
lost, what difference does it make if you don’t know I am steering you?
This outlook has led to a widespread preference among nudgers for
“moving in imperceptible steps that do not create backlash or
resistance” as Andreas Souvaliotis, the executive chairman of Social
Change Rewards, recently said in an interview in Forbes. Remove
the assumption that people are inescapably mistaken, though, and the
justification for this kind of sneakiness disappears. And that suggests a
whole different direction for nudge. Call it Nudge 2.0: Corporate
messages and government policies that increase awareness about how the
mind works, rather than depending on people not to notice. As it is with
the slime mold or the capuchin monkey, the decoy effect might be
irresistible to us all. But at least we can understand what we’re doing
when we succumb to it.
