Mid Semester Flashcards
What are the key assumptions of microeconomics?
1) people are rational
2) people are self interested
3) utility is calculated as the weighted benefits
4) linearity in probabilities
5) people use and interpret information perfectly
6) exponential discounting
7) Only final outcomes matter
What is neoclassical utility
Eu = p u(x) + p u (y) + …. + p u(n)
as long as positive all decision makers (including risk averse) would take the rise
What does linear in probabilities mean?
the weight attached to an outcome is proportional to the probability of it occurring. This means that an outcome with twice the probability is weighted twice a much, regardless of how likely it was n the fist place
What is reference dependent preferences?
Economic agents evaluate their level of utility against a reference point and are loss averse to their reference point.
What is loss aversion?
The disutility stemming from falling behind your reference point is larger than the utility generated by an equal sized gain (asymmetric)
What is diminishing sensitivity?
Agents are less sensitive to changes the further away they are from their reference point
What is over weighting of small probabilities
People tend to put more weight on remote but meaningful outcomes that neoclassical would suggest. For example, people would prefer to lose a small amount of money for sure than face the small possibility of losing a large amount of money (loss aversion)
What is the certainty effect?
People are sensitive to changes from a sure thing to a probability smaller than 1 but are not overly sensitive to changes between intermediate probabilities.
What is the probability weighting function
Kahneman and Tversky challenge the neoclassical linear probabilities by making a new function with incorporates both over weighting of small probabilities and the certainty effect (kind of s shaped)
Increasing function that is steepest near 0 and 1.
What is prospect theory?
an outcome c is evaluated relative to a reference point, r, according to a value function (v (c - r)), The function incorporates loss aversion (a symmetric, kink at 0) and diminishing sensitivity (logish function ehich flattens off)
Why isn’t risk aversion a valid explanation for why economic agents (even rich) don’t take a fair gamble?
Would have to be too risk averse to make everyday investment decisions. Even $500 is small when considering life-time savings and diminishing marginal utility is flat at this time.
What do we find about consumption smoohting
Neo: people smooth consumption over their lives so that permenant changes to future income is met weith changes in today’s consumption
Evidence: people tend not to do this - people’s consumption drops sharply towards end of pay period or following retirement. Even with announced wage agreements consumption tends not to decrease in anticipation
Behavioural: reference is current income. Consuming more in response to future increase makes them happy but cutting down on consumption is hard so they delay reducing it
What are 3 theories about determining reference points?
1) lagged consumption or endowment
2) aspirations and goals
3) social comparisons
The first two can be unifies in terms of recent expectations (subjects expect to keep what they receive so being endowed with a mug sets their reference points and expect to earn what they did in the previous year or fulfilling reasonable goals for these
What is the endowment effect?
fact that owners value a good more than otherwise identical non-owners. The fact that you own it makes it more valuable to you (manifestation of loss aversion)
What is intertemporal choice
Choice over time?
What is hyperbolic discounting?
People are short run impatience but long run patience, leading to self-control problems and inconsistency
How are choices over time made in neoclassical economics?
Interest rate is the relative price of consumption today versus tomorrow (Fisher Curve).
Samuleson proposed the discounted utility whereby people maximise utility across a lifetime but future periods are discounted on an exponential basis.
What does gamma represent
long run discount factor (only factor in neoclasssical). Represents the willingness to delay to delay gratification The smaller gamma is, the less people value future consumption relative to current consumption.
What is the key implication of exponential discounting
People are dynamically consistent (that is, when an agent makes a choice about the future, that choice is still the preferred option when the future arrives)
What are some problems with exponential discounting
1) in 10 periods, value at x^10 which is generally ridiculous
2) data shows that people are dynamically inconsistent
3) psychological workings distilled into just one parameter
What is the payday effect?
People spend a large proportion of their income immediately after getting paid and cut down consumption dramatically towards the end of the pay period rather than smoothing their consumption
Some people even take out expensive loans to finance current consumption