Title: Cognitive Economics
1Cognitive Economics
- Miles Kimball
- University of Michigan
- Presentation at Osaka University
2Definition of Cognitive Economics
- The Economics of What is in Peoples Minds
3Named by Analogy to Cognitive Psychology
- Cognitive Psychology the area of psychology
that examines internal mental processes such as
problem solving, memory and language. - Cognitive Psychology was a departure from
Behaviorism--the idea that only outward behavior
was a legitimate subject of study.
4How is Cognitive Economics Different from
Behavioral or Psychological Economics?
- Cognitive economics is narrower.
- Much of cognitive economics is inspired by the
internal dynamic of economics rather than by
psychology. - Cognitive economics is a field of study, not a
school of thought.
5Areas of Economics by Distinctive Data Type
- Standard Economics (including Mindless
Psychological Economics a la Gul and
Pesendorfer) actual market choices only. - Experimental Economics choices in artificial
situations but with real stakes. - Neuroeconomics FMRI, saccades, skin conductance,
- Bioeconomics genes, hormones
- Cognitive Economics mental contents (based on
tests and self-reports) and hypothetical choices.
6Four Themes of Cognitive Economics
- New Types of Data
- Heterogeneity
- Finite and Scarce Cognition
- Welfare Economics Revisited
71. Innovative Survey Data
- fluid intelligence data
- crystallized intelligence data
- happiness data
- survey measures of expectations
- survey measures of preferences
82. Individual Heterogeneity
- heterogeneous expectations
- heterogeneous preferences
- heterogeneous emotional reactions
- heterogeneous views on how the world works (folk
theories)
93. Finite and Scarce Cognition
- Finite cognitionthe reality that people are not
infinitely intelligent. - Scarce cognitionsome decisions required by our
modern environmentat work and in private
livescan require more intelligence for
full-scale optimization than an individual has
104. Welfare Economics Revisited
- Scarce cognition means that people sometimes make
mistakes. Thus, one can no longer use naïve
revealed preference for welfare economics. - Kimball and Willis, in Utility and Happiness,
argue that happiness data is not a magical
touchstone for diagnosing mistakes. - Then, what does count as evidence of mistakes?
- Internal inconsistencies, such as lack of
transitivity? But which choice then deserves
respect? - Regret?
- Modification of choices after experience?
- Differences in choices between those with high
cognitive ability and those with low cognitive
ability? - e.g., Dan Benjamin and Jesse Shapiro show that
low IQ students had more low-stakes risk aversion
and short-horizon impatience
11Some Research Questions in Cognitive Economics
- Seek to make innovations in economic theory and
measurement to address - What are peoples limitations in knowledge,
memory, reasoning, calculation? - What is the role of emotion, social context,
conscious vs. unconscious judgments and
decisions? - What is the role of health as determinant,
outcome and context for economic activity,
decisions and well being? - What is connection between economic welfare and
measures of well being? - Etc.
12New Types of DataMeasurement of Cognition in
the HRS
- HRS has included cognitive measures from the
outset, but mostly focused on memory in order to
trace cognitive decline. - Re-engineering HRS cognitive measures
- Led by Jack McArdle, a cognitive psychologist and
HRS co-PI, we have begun a project to
re-engineer our cognitive measures in order to
improve our understanding of the determinants of
decision-making about retirement, savings and
health and their implications for the well-being
of older Americans
13New Types of Data Measurement of Cognition in
the HRS (cont.)
- Separate HRS-Cognition Study
- Begins with a separate sample of 1200 persons age
50 who will receive about three hours of
cognitive testing of their fluid and crystallized
intelligence plus parts of the HRS questionnaire
on demographics, health and cognition - Followed a month later by administration of an
internet or mail survey of questions designed by
economists on financial literacy, ability to
compound-discount, hypothetical decisions about
portfolio choice, long term care - Finally, telephone follow-up with HRS cognition
items and subjective probability questions - Analysis of data will guide re-engineering of
cognitive items for HRS-2010
14New Types of Data Survey Measures of Expectations
- What is the mapping between probability beliefs
in peoples minds and the decisions they make?
(Robert Willis, Charles Manski, Mike Hurd, Jeff
Dominitz, Adeline Delavande)
15Direct Measurement of Subjective Probability
Beliefs in HRS
Probability questions use a format pioneered by
Tom Juster and Chuck Manski
(Manski, 2004)
HRS Survival Probability Question Using a
number from 0 to 100, what do you think are the
chances that you will live to be at least target
age X? X 80 for persons 50 to 70 and
increases to 85, 90, 95, 100 for each five year
increase in age
16Two Key Findings From Previous Research on HRS
Probability Questions
- 1. On average, probabilities make sense
- Survival probabilities conform to life tables and
are - predictive of actual mortality
- (Hurd and McGarry 1995,
2002 Sloan, et. al., 2001 ) - Bequest probabilities behave sensibly
- (Smith 1999), Perry (2006)
- Retirement incentives can be analyzed using
expectational data - (Chan and Stevens, 2003)
- People can predict nursing home entry
- (Finkelstein and McGarry,
2006) - Early Social Security Claiming Depends on
Survival Probability - (Delevande, Perry and Willis,
2006) , (Coile, et. al., 2002) - 2. Individual probabilities are very noisy with
heaping on focal values of "0", "50-50" and "100
- (Hurd, McFadden and Gan, 1998)
1710 Year Mortality Rate vs. Subjective Survival
Probability to Age 75
Odds Ratio of Death by t10
Subjective Survival Probability at Time t
Source Mortality Computations from HRS-2002 by
David Weir
1810 Year Mortality Rate vs. Subjective Survival
Probability to Age 75
Strongest relationship between subjective and
objective risks for people with low subjective
survival beliefs
Odds Ratio of Death by t10
Subjective Survival Probability at Time t
Source Mortality Computations from HRS-2002 by
David Weir
19. Histograms of Responses to Probability
Questions in the HRS
A. General Events Social Security less
generous Double digit inflation B. Events
with Personal Information Survival to 75
Income increase faster than inflation C.
Events with Personal Control Leave
inheritance Work at age 62
20Are Benefits of Greater Individual Choice
Influenced by Quality of Probabilistic Thinking?
- Trend of increasing scope for individual choice
in public and private policy, especially as it
affects those planning for retirement or already
retired - Private sector shift from defined benefit to
defined contribution pension plans - Proposals for individual accounts in Social
Security - Choice of when/whether to annuitize
- Choice of medical insurance plans and providers
by employers and by Medicare, new Medicare
Prescription Drug program - Economists generally view increased choice as a
good thing, but - General public wonders whether people will make
wise use of choice - Decisions faced by older individuals balancing
risks and benefits of alternative financial and
health care choices are genuinely difficult
21Quality of Probabilistic Thinking and Uncertainty
Aversion
- Lillard and Willis (2001) began to look at the
pattern of responses to probability questions as
indicators of the degree to which they indicate
peoples capacity to think clearly about
subjective probability beliefs - We explored the idea that focal answers of 0,
50 and 100 were perhaps indicators of less
coherent or well-formed beliefs than non-focal
(or exact) answers.
22Index of Focal Responses
- We treated the probability questions like a
psychological battery and constructed an
empirical propensity to give focal answers of
0, 50 or 100
We found that people who had a lower
propensity to give focal answers tended to have
higher wealth, had riskier portfolios, and
achieved higher rates of return, controlling for
conventional economic and demographic variables
23Uncertainty Aversion
- We hypothesized that people who give more focal
answers are more uncertain about the true value
of probabilities - If the uncertainty is about a repeated risk, such
as the return to a stock portfolio held over
time, we show that people who have more imprecise
probability beliefs (i.e. are more uncertain
about the true probability) will behave more
risk aversely
24Some Further Results on Subjective Probabilities
- There is optimism factor common across all
probability questions which is correlated with
stock-holding and associated with being healthy,
wealthy and wise - Kezdi and Willis (2003)
- HRS has added direct questions on stock returns
- stockholding is related to probability beliefs
- Kezdi and Willis (2003) and Dominitz and Manski
(2006) - most people do not believe that stocks have
positive returns, despite the equity premium that
economists know about - Persons who provide more precise probability
answers also exhibit less risk aversion on
subjective risk aversion questions in the HRS,
and they save a higher fraction of their full
wealth. - Sahm (2007), Pounder (2007)
- In 2006, HRS added questions to those who answer
50 to see whether they mean equally probable
or just uncertain. 75 indicate they are
uncertain.
25New Types of Data Survey Measures of
Preferences Based on Hypothetical Choices
- Examples
- Labor Supply Elasticities,
- Altruism,
- Social Rivalry,
- Risk Aversion,
- Elasticity of Intertemporal Substitution
26Does Risk Tolerance Change?
- Claudia Sahm
- University of Michigan?Board of
- Governors
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50Measuring Time Preference and the Elasticity of
Intertemporal Substitution
- Miles S. Kimball, Claudia R. Sahm and Matthew D.
Shapiro
September 6, 2006 Internet Project Meeting
51Behavioral Model
- c is consumption,
- r is the real interest rate,
- s is the elasticity of intertemporal
substitution, and - ? is the subjective discount rate
52Research Design
Estimate Parameters s, ?
53Implementation
- Vary Interest Rate
- Vary cost of current consumption
- Vary length of time periods
- Measure Consumption Choice
- Choose among small set of paths
- Actively form a desired path
- Infer Preferences
- Summary statistics of responses
- Statistical model with response error
54Previous Survey Measures
- HRS 1992 Module K, N 198
- Analyzed by Barsky, Kimball, Juster, and Shapiro
(QJE 1997) - HRS 1999 Mailout, N 1,210
- Similar content to part of Internet Survey
Questions explicitly vary the cost of current
consumption and offer a discrete choice over a
small set of consumption paths
55MS Internet SurveyWave 2 (Fall 2004)
Use graphics on Internet to test other measures
- Version 1, N 350
- Vary cost of consumption
- Choose from set of pairs
- Version 2, N 155
- Vary cost of consumption
- Move bars to create pair
- Version 3, N 183
- Vary length of period
- Move bars to create pair
56Series Introduction - Version 1 -
- Series includes four questions with varying
interest rates
57Introduction 0 Interest Rate
- Sequence r 0, 4.6, 9.2, 13.8 is random
- Introduction repeated for each interest rate
58Patterns 0 Interest Rate
- Asked to choose two patterns
- Above screen (1 of 6) is identical to HRS Mail
Out
59Expansion Screen
- Follow-up if first choice on boundary (A or E)
60Randomize Pair C
- Choice C positive, zero, negative growth rate
- 3 values to the parameter
- New feature on Internet
- Top screen on mail out
61Randomize Left-to-Right
- Growth rates increase or decrease left-to-right
- New feature on Internet
- Top screen on mail out
62Randomize Shifts with Interest Rate
- Example with r 9.2
- Choice of (2750, 3900) moves from E to C to A
- 3 values to the parameter
- New feature on Internet
- Middle screen on mail out
63Summary of Innovations in Internet Question
Series
- 18 different screen groups
- 6 different sequences of interest rates
- 11 discrete choices per question
Purpose of Innovations
- Encourage active choices
- Increase informative responses
- Isolate framing effects
64Response Statistics
- Internet lower completion rate
- Internet fewer second choices
- Internet fewer non-informative responses
65Consumption Growth at 0 Interest Rate
- Constant consumption is modal choice
66Change in Consumption Growth as Interest Rate to
13.8 from 0
- Interest rates change consumption more on Internet
67Change in Consumption Growth as Interest Rate
Increases - Internet
- Decrease in growth is a sign of survey response
error
68Estimates of Parameters
- Responses reveal low time preference and IES
- Median and modal values in both surveys equal 0
69Effect of Changes in Choice Set
70Estimates by Screen Group
71More Graphical Questions- Version 2 -
- Move bars to select a consumption path
72More Graphical Questions- Version 3 -
- Vary length of current and future periods
73Extensions / Renewal
- Measure complementary parameters
- Diminishing marginal utility
- Labor supply elasticities
- Retirement elasticity
74Four Themes of Cognitive Economics
- New Types of Data
- Heterogeneity
- Finite and Scarce Cognition
- Welfare Economics Revisited
75Bounded Rationality vs. Scarce Cognition
- Same meaning, but bounded rationality seems a
misnomer, since it is rational to recognize ones
own cognitive limitations. - Two obstacles have prevented Bounded
Rationality from becoming part of the mainstream - theoretical difficulties stemming from the
importance of constrained optimization as a
theoretical tool in economics - paucity of data
- Scarce Cognition is meant to label a data-rich
research agenda, using new theoretical tools.
76The Reality of Finite Cognition
- Computers beat us at chess
- People dont get perfect scores on tests, even
after they have studied the material - For hundreds of years, we had no proof of
Fermats last theorem
77The Reality of Scarce Cognition
- Many people
- spend time and money learning math
- pay others with higher wage rates to do their
taxes - pay others to read law books for them
- pay for financial advice
78Modeling Scarce Cognition is Hard The Infinite
Regress Problem (Conlisk)
- It is natural for economists to assume a cost of
computation, just like any other costso why not
more such models? - Answer figuring out how hard to think about a
problem is always a strictly harder problem than
the original problem - Need the solution to the original problem to
calculate the benefit - Need to know how to solve the problem to know how
many computational steps it needs
79Dodging the Infinite Regress Problem by Breaking
Taboos
- Ignoring computational costs at the outer level.
(Maybe OK if the original problem is a repeated
choice.) - Using limited information transmission capacity
as a metaphor for limited intelligence. (A
thick skull.) - Subhuman intelligence
- --agent-based modeling
- --rules of thumb (adaptive expectations, consume
income, statistical models) - Modeling folk theories ignorant of the maintained
hypotheses
80Modeling Unawareness Requires a Subjective State
Space Distinct from the True State Space
- (Dekel, Lipman and Rustichini)
- economic actor subjective state space
- analyst state space maintained as true
81Two Levels of Theory
- Folk theory economic actors theory modeled in
the subjective state space - May look like an accounting framework in the
sense of Herrnstein and Prelec in The Matching
Law - Metatheory the analysts theory which includes a
description of the relevant folk theories. - Preferences
- Technology
- Available Strategies
- Active Information Structure
- Folk Theories
82Desirable Properties for a Model of a Folk Theory
- Accuracy in describing how people actually view
the world - Providing a clear prediction for how people will
behave in various circumstances - Representing clearly how people are confused and
what they do understand. - NOT REQUIRED deep logical consistency
83An Example of Folk Physics
- Many people believe that if they swing a stone
around on a string and let it go, then the stone
will curve sideways in the direction they were
swinging it around. - Other than going up and down in the vertical
direction, it actually goes straight once
released.
84An Example of Folk Finance
- It Misses These Ideas
- Link of diversification to the
- variance/covariance matrix
- 2. Diversification makes it safe
- enough to hold a lot of the
- risky asset
- 3. Role of human capital
- 4. Consumption as the ultimate
- objective
- This Folk Theory Models
- Three Ideas
- Mean return is good
- Risk is bad
- Diversification is good
I
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93Household Finance and Welfare Economics The
Possibility of Strong Normative Statements
- Fungibility money is money
- At the end of the day, only the total value of
the portfolio matters, not the separate value of
its constituent parts. - Fungibility is a legal term OK to pay back a
different piece of currency as long as the value
is the same. (Not like a diamond ring) - Very basic principle in economics fungibility of
money is assumed in standard treatments of
revealed preference - Noneconomists do not always understand
fungibility mental accounts
94High and Low Savers? Circumstances, Patience, and
Cognition
95Differences in Consumption (Saving) Rates Across
Households
- Circumstances?
- Such as income shocks differences in pensions
(income replacement rate in retirement) income
profiles etc. - Or Types of Savers?
- By inherent characteristics such as
preferences or ability/cognition
96Getting Past Circumstances
- Circumstances create cross-household variation
when measuring rates C/Income or C/NetWorth - Difficult to isolate role of preferences or other
inherent differences across households
97The Right Rate Consumption and Full Wealth
- Lifecycle/PIH theory since Modigliani says
consumption should depend on all current and
future resources (including financial and human
wealth.) - Like a stock value of permanent income from today
forward - I call this PV of all resources
- Modigliani full wealth M
98Data Allows Comparison Testing
- A credible estimate of M for older households,
together with consumption, available for the
first time in the HRS - Compare observed propensity to consume C/M to
neoclassical model of optimal consumption rates - Use survey estimates of models factors that vary
across households to indicate which factors play
largest role in explaining observed variation in
C/M
99Neoclassical Model (Merton 1971)
- Mortality and rate of return the only sources of
uncertainty
Subject to
Estimate mortality with Gompertz function ?age
?1 e(?2age)
100Average Propensity to Consume
Infinite Horizon (no mortality)
- Implications
- C is proportional in M
- C/M depends only on preferences, stochastic
return characteristics, and mortality. - C/M does not depend directly on M, income
profile, or outcome of past income shocks
101Findings
- Survey estimates of model factors matter in
expected direction - Heterogeneity in observed C/M! Rich save more
(lower propensity to consume) - Inherent characteristics or types important in
explaining C/M - Within neoclassical/rational model must have
heterogeneous time preference to explain C/M - Looking outside standard model cognition
planning matter to C/M
102Model Factors
Dependent Variable ln(C/M) (1) (2)
Log Predicted C/M with variation by mortality only 0.013 (0.002)
Log Predicted C/M with variation by mortality and expected risky returns 0.017 (0.002)
N1842 R20.023 R20.027
103Adding Survey Measures of Model Factors
Dependent Variable ln(C/M) with additional demographics with additional demographics with additional demographics
Subjective Life Expectancy Ratio -0.137 (0.044) -0.080 (0.043)
Probability of Bequest gt10k (Continuous) -0.002 (0.001)
Probability of Bequest gt100k (Continuous) -0.003 (0.001)
Risk Aversion Survey Measure -0.022 (0.007)
Model Prediction 1.33 (0.363) 1.04 (0.359) 1.45 (0.454)
Constant 3.69 -3.55 -5.77
R20.231 R20.287 R20.226
N1190 N1190 N894
104Rich Save MoreC/M Varies by Income or Wealth
Level
105Beyond the Neoclassical ModelAbilities
Cognition Planning
- Bounded cognition
- Propensity to plan
- Expectations formation
- (Lusardi, LillardWillis, CaplinLeahy)
106Measures in HRS
- HRS asks questions on basic cognition (recall,
counting, subtraction) plus planning horizon and
subjective expectations - Lillard Willis focal point answers
precision of expectations formation related to
financial decisions - Measures matter such that lower cognition, less
precision, and shorter planning horizons all
imply higher propensities to consume
107Cognition/Planning Predict C/M
Dependent Variable Residual of ln(C/M) after full regression
Long Financial Planning Horizon -0.070 (0.028)
Fraction of Precise Answers -0.088 (0.053)
High Word Recall -0.062 (0.030)
Counting Backwards -0.124 (0.048)
Hardest Subtraction Problem -0.049 (0.030)
N1645 R20.027
Â
108Further Evidence Loosely Related Preference
Covariates
Dependent Variable Residual of ln(C/M) after full regression
Ever Smoked 0.046 (0.028)
Reports would Spend all of hypothetical income increase 0.091 (0.053)
Reports would Save all of hypothetical income increase -0.055 (0.031)
N1645 R20.01
Dependent Variable Residual of ln(C/M) after full regression Dependent Variable Residual of ln(C/M) after full regression Dependent Variable Residual of ln(C/M) after full regression Dependent Variable Residual of ln(C/M) after full regression Dependent Variable Residual of ln(C/M) after full regression Dependent Variable Residual of ln(C/M) after full regression
Personality Questions
Seldom apprehensive about future 0.028 (0.022) 0.048 (0.023)
Strive for excellence -0.097 (0.024) -0.109 (0.029)
Clear set of goals and work toward them -0.026 (0.023) -0.006 (0.025)
Work hard to accomplish goals -0.063 (0.034) -0.011 (0.039)
N235 N235 N235 N235 N235 N235