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NeuroEconLab

Temporal Discounting & Time Preference Task
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Welcome to the Temporal Discounting Experiment

In this task, you will make decisions between receiving a Smaller Amount Today or a Larger Amount ($100) in the Future at various time delays.

Instructions:
  • There are no right or wrong choices; select based on your genuine preferences.
  • You will complete 14 binary intertemporal choices presented in randomized order.
  • Your personal Discount Rate ($k$), Subjective Value curves, and Impulsivity Index (AUC) will be computed live!
Trial 1 / 14 Delay: 1 Month (30 Days)

Which reward payout option do you prefer?

Option A (Smaller Sooner)

Receive Immediately

$50
Paid Today
(0 Days Delay)
Option B (Larger Later)

Receive in the Future

$100
30 Days
Delay Period
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Experiment Completed!

Your time choices have been registered and fitted against Hyperbolic and Exponential discounting models.

Hyperbolic Rate ($k$)
0.0050
Daily discount factor
Half-Life Value ($T_{1/2}$)
200 Days
Days until $100 feels like $50
Area Under Curve (AUC)
0.65
Model-free index (0 = Impulsive, 1 = Patient)
Present-Bias Index ($\beta$)
0.90
Immediate vs future markup

Moderately Patient Profile

You balance immediate gratification with long-term financial growth.

1. Subjective Value Discounting Curve $V(D)$
2. Area Under the Curve (AUC) Profile

Export Submission File

Download your decision dataset and complete analytical summary for assignment submission.

Model Parameters

Patient (0.0001) Impulsive (0.03)
$\beta < 1.0$ indicates special premium on immediate rewards.
Decision temperature / choice variance.
Preset Archetypes:
Simulated Hyperbolic vs. Quasi-Hyperbolic Curve
Simulated Probability P(Choose $X Now vs $100 at Delay)

Neuroeconomics Framework & Mathematical Discounting Models

1. Exponential Discounting (Standard Economics)

Standard normative economic theory assumes a constant discount rate over time:

V(D) = A · e-\delta D

Implies time-consistent preferences: if you prefer $100 in 31 days over $90 in 30 days, you must also prefer $100 in 1 day over $90 today.

2. Mazur Hyperbolic Discounting Model

Empirical behavioral research demonstrates that humans discount the immediate future much steeper than distant futures:

V(D) = A / (1 + k · D)

Where $A$ is the objective amount ($100), $D$ is delay in days, and $k$ is the individual discount parameter representing impulsivity.

3. Quasi-Hyperbolic ($\beta$-$\delta$) Present-Bias Model

Captures the dual-system neurobiological model of decision making:

V(0) = A,    V(D) = β · δD · A   (for D > 0)

$\beta < 1.0$ models the emotional "present-bias" driven by the limbic system / ventral striatum when rewards are immediate.

4. Area Under the Curve (AUC)

A model-free, non-parametric measure of discounting (Myerson et al., 2001):

AUC = ∑ (xi+1 - xi) · [ (yi + yi+1) / 2 ]

Delays ($x$) and Subjective Values ($y$) are normalized between 0 and 1. Values close to 1 indicate high patience; values near 0 reflect extreme impulsivity.