VIRTUAL EXPERIMENTS IN ECONOMICS A METHODOLOGICAL ASSESSMENT

Alessandro Innocenti(University of Siena)

To propose Low immersive virtual experiments (LIVE) as

tools for experimental economics where the laboratory

approach has important limitations.

To explore the potentiality of LIVE by providing the

preliminary findings of two specifically designed

experimental studies investigating risk propension under

social exposure and risk perception in workplaces.

Paper’s purpose

Failures of Lab Experiments

The Context-Free Bias

Virtual Experiments

The ALBO Project

Results

Conclusions

Talk Outline

a) situations are not really presented, but only

described through language

b) choices and decisions are only to be evoked, not to

be really performed

c) there is a lack in the normal cascade of events as

actions and reactions

d) temporal frame is generally compressed

e) irrelevance of the context

Failures of Lab Experiments

Many experimental economists seem to view their

enterprise as akin to silicon chip production. Subjects are

removed from all familiar contextual cues. Like the

characters 'thing one' and 'thing two' in Dr. Suess' Cat in

the Hat, buyers and sellers become 'persons A and B', and

all other information that might make the situation familiar

and provide a clue about how to behave is removed.

George Loewenstein (1999)

Lab as silicon chip production

The context-free experiment is an elusive goal

A major tenet of cognitive psychology is how all forms of

thinking and problem solving are context-dependent

The laboratory is not a socially neutral context, but is itself

an institution with its own formal or informal, explicit or

tacit, rules

Games in the laboratory are usually played without labels

but subjects inevitably apply their own labels

The context-free bias

Labels can increase experiment’s external validity with a

minimal sacrifice of internal validity

In particular, to test learning and cognitive models, it is

necessary to remind and to evoke contexts which may

activate emotions, association, similarities in the

laboratory

Labels can make subjects more or less rational in

relation to the evoked context

The power of labels

Jones-Sugden Theory and Decision (2001)

Positive confirmation bias: tendency, when testing an existing belief, to search for evidence which could confirm that belief, rather than disconfirming it

The original selection Wason’s task was formulated in highly abstract terms

Correct response was facilitated by adding thematic content to the task, i.e. a cover story which accounts for the statement and gives some point to the task

Labels make subjects more rational

Innocenti-Pazienza-Lattarulo Transport Policy (2013)

Main finding: Subjects’ inclination to prefer cars over bus and metro tends to override the incentives’ effect

Laboratory behavior depends more on prior learning outside the laboratory than on gains in the laboratory

In the experiment, it is as if subjects take into the lab the preferences applied to real choices between car, bus and metro and stick to them with high probability

Labels give subjects clues to become less and not more rational

Labels make subjects less rational

The use of presentations with virtual reality (VR) simulations can convey objectively this kind of context

“A Virtual Experiment is an experiment set in a controlled lab-like environment, using typical lab or field participants, that generates synthetic field cues using Virtual Reality (VR) technology.” Fiore, Harrison, Hughes and Rutström (2009) FHHR (p. 66)

Virtual experiments are not defined as just those occurring over the web (Virtual Worlds experiments as a subset of Virtual Experiments)

Virtual Experiments (VE)

Virtual Experiment combines insights from virtual reality (VR) simulations in computer science, decision making and ecological rationality from psychology, and experiments from economics

The methodological objective of Virtual Experiments is to combine the strengths of the artificial controls of lab experiments with the naturalistic domain of field experiments

Virtual Experiments (VE)

High Immersive Virtual Experiments (HIVE) utilize specialized displays such as CAVE, head-mounted displays or augmented reality, which perceptually surround subjects. The individual perceives himself to be enveloped by, included in, and interacting with an environment providing a continuous stream of stimuli

Desktop or Low Immersive Virtual Experiments (LIVE) use computer screen based applications of virtual reality, such as “ad hoc” virtual simulations or virtual worlds (Second Life) to provide a weaker sense of presence.

High and Low Immersive VE

Cave (HIVE)

Head-Mounted Display (HIVE)

Virtual simulations (LIVE)

Bateman et al. 2009In the majority of choice experiments on gain-loss asymmetry (WTA>WTP) the attributes of non-market goods are conveyed to respondents as a table of numeric and/or categorical data.

Compared to the standard presentation, preferences elicited in the Virtual Experiment are less variable and exhibit a significant reduction in asymmetry between willingness to pay for gains and willingness to accept for corresponding losses.

Applications – Gain/Loss Asymmetry

Virtual Rural Areas (Bateman 2009)

Fiore et al. (2009)Virtual Experiment to elicit risk perception from wild fires and the opportunity cost of public funds allocated to prescribed burns

Subjects experience four dynamic visual simulations of specific wild fires, with varying weather and fuel conditions. Simulations are selected to represent high and low risk of fire damage

Participants experience a sense of presence, a psychological state of “being there and take decisions closer to real behavior” (with cognitive constraints )

Applications – Risk Perception

Wild fires renderings (Fiore 2009)

Main objectives

To demonstrate that the standard tools for detecting work-related factors of risk and stress (questionnaires and interviews) are inadequate to capture workers’ real perception

To prove that virtual and low immersive simulations of work environments provide a better awareness of psycho-social risks in workplaces

ALBO Project

Experiment 1Individual risk attitude under social exposure in the lab is modified by the presence of a virtual coach

Experiment 2Workers’ awareness of biases in risk perception is enhanced by virtual simulations of their work activities

ALBO Research Findings

Yechiam et al. “Observing others’ behavior and risk taking in decisions from experience”, JDM 2008

choice between safe and risky option two tasks: rare-loss and equiprobable-loss exposure vs. no-exposure condition observer vs. source role

Main finding: Observing others’ choices increases observer’s risk propensity

Experiment 1 - Background

Between-subject

52 undergraduate students (avg 22 y.)

Two subjects randomly and anonymously paired

playing as source and observer

30 repeated choices (alternate):

15 rare (equiprobable) gains

15 rare (equiprobale) losses

Comparison between source and observer condition

Experiment 1 - Design

Experiment 1 - Tasks

Table 1 Experimental design

Rare Gain-Loss Condition Equiprobable Gain-Loss Condition

Problem 1.

Rare

Gain

Problem 2.

Rare

Loss

Problem 3.

Equiprobable

Gain

Problem 4.

Equiprobable

Loss

Safe

option

(S)

Gain 2 tokens

(EV = 2)

Lose 2 tokens

(EV = -2)

Gain 2 tokens

(EV = 2)

Lose 2 tokens

(EV = -2)

Risky

option

(R)

Gain 30 tokens

(prob. 5%)

or

Gain 1 token

(prob. 95%)

(EV = 2.5)

Lose 30 tokens

(prob. 5%)

or

Lose 1 token

(prob. 95%)

(EV = -2.5)

Gain 4 tokens

(prob. 50%)

or

Gain 1 token

(prob. 50%)

(EV = 2.45)

Lose 4 tokens

(prob. 50%)

Or

Lose 1 token

(prob. 50%)

(EV = -2.45)

Observers are more risk-lovers than sources also

for gains (as for losses in Yechiam et al. 2008)

Both roles are risk averse for losses and risk loving

for gains

No significant difference between rare/equiprobable

condition (differently from Yechiam)

Faster reaction time for sources

Personality traits (Big Five Questionnaire) matters

Experiment 1 – Main Findings

VS..

LIVExp 1 - Design

LIVExp 1 – Results

No significant differences in risk attitudes between

observers and sources

Both roles are confirmed as risk averse for losses

and risk loving for gains

No difference in reaction time across roles

Virtual environments are perceived as an intermediate

safe environment and allow structuring therapy like a

special and protected environment (Botella et al. 2008)

The Proteus Effect: deindividuation occurs in online

environments because users may adhere to identities

inferred from their avatars (McKenna & Bargh 2000,

Yee-Bailenson 2007)

Deindividuation can also lead to both prosocial and

antisocial behavior (Zimbardo 1969, Gergen et al. 1973).

LIVE Exp 1 – Interpretation

Differences between observers and sources are removed because the virtual coach make subjects’ choices less influenced by laboratory cues

The potentially worrisome desire to please the experimenter is attenuated because no embodiment of the experimental team appears in the lab

Virtual environment enables experimenter to focus subjects on experimental tasks

By allowing participants to take on natural roles in economic settings, virtual worlds can help subjects to focus on the laboratory task

LIVE Exp 1 – Interpretation

Virtual Movies vs. Real Movies in the Assessment of Work Related Stress

Obj.: to verify the presence of differences in the physiological and cognitive activations while subjects watch real movies vs. virtual movies

Hp.: Vision of virtual movies is associated with a lower physiological activation, a more detailed narrative and a greater detection of ‘errors’, thanks to a more objective perspective.

LIVExperiment 2

Between-subject 20 postgraduate students + 16 professional workers 2 Conditions: Real clip of a job stress situation + Virtual simulation of the same clipsDetection of three physiological indices:

Heart rate Electromyography (EMG), measures the electrical

impulses of face muscles at rest and during contraction

Skin Conductance LevelQuestionnaire Generalized Self-Efficacy and Locus of Control (beliefs about control of events)

LIVExperiment 2 - Design

LIVExperiment 2

LIVExperiment 2 – HR

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

25

HR

FC Avatar FC Reale

LIVExperiment 2 – EMG

1 2 3 4 5 6 7 8 9 10 110

2

4

6

8

10

12

14

EMG

EMG Avatar EMG Reale

Physiological activations (HR and EMG) are

significantly lower under virtual simulations

Limitations: Small sample and the use of pilot

movies

Research Implications: Results obtained through

the use of virtual reality tools allow to design stress

assessment interventions and online training

courses with virtual coaches

LIVExp 2 – Preliminary Findings

To test if subjects’ behaviour in VE conforms to results generated in conventional experimentation

“Virtual experiments might be more convenient than lab experiments if he sees people behave in he same way in real-world and virtual experiments” (List 2007)

“Determining where virtual world behavior mimics real world behavior is quite important for methodological reasons. If virtual world behavior can be treated as a model of human behavior in general, this would allow a fresh approach to empirical social science” (Castronova 2008)

Main Approach to VE

More naturalistic and less simple settings than

laboratory

Cheaper to maintain virtual laboratory facilities

Easier to control decision tasks and enviroments

No involuntary non-verbal communication

Wider and unbiased population

Virtual Experiments - PROS

Virtual situations project a game-like atmosphere

Proteus effect / deindividuation (may be an asset)

it is difficult to establish subject trust in computer

software

(virtual worlds experiments) subjects’ identity is not

checked because physical presence is lacking

Virtual Experiments - CONS

The difference between virtual and laboratory experiments and between virtual and real behavior is an asset rather than a problem for experimental economics.

It can very helpful in solving some failures of lab experiments

Ir/relevance of the context Intertemporal choice – longtime experiments Heterogeneous subject pools Cross-cultural and professional comparisons

Conclusions

Induced-value theory: use of a reward medium allows to induce pre-specified characteristics in experimental subjects and to make subjects’ innate characteristics largely irrelevant (Smith 1992)

The central aspect of the VX methodology is a VR environment that makes participants experience a sense of presence, a psychological state of ‘‘being there.’’ This sense depends on the degree of involvement that participants experience as a consequence of focusing attention on the set of stimuli and activities generated by the VR simulation.

(Fiore et al. 2009)

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