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66 changes: 66 additions & 0 deletions lectures/_static/quant-econ.bib
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,62 @@
Note: Extended Information (like abstracts, doi, url's etc.) can be found in quant-econ-extendedinfo.bib file in _static/
###


@article{harsanyi1968games,
title={Games with Incomplete Information Played by ``{B}ayesian'' Players, {I}--{III} Part {II}. {B}ayesian Equilibrium Points},
author={Harsanyi, John C.},
journal={Management Science},
volume={14},
number={5},
pages={320--334},
year={1968},
publisher={INFORMS}
}

@article{harsanyi1968games3,
title={Games with Incomplete Information Played by ``{B}ayesian'' Players, {I}--{III} Part {III}. {T}he Basic Probability Distribution of the Game},
author={Harsanyi, John C.},
journal={Management Science},
volume={14},
number={7},
pages={486--502},
year={1968},
publisher={INFORMS}
}

@article{harsanyi1967games,
title={Games with Incomplete Information Played by ``{B}ayesian'' Players, {I}--{III} Part {I}. {T}he Basic Model},
author={Harsanyi, John C.},
journal={Management Science},
volume={14},
number={3},
pages={159--182},
year={1967},
publisher={INFORMS}
}

@article{miller1977risk,
title={Risk, uncertainty, and divergence of opinion},
author={Miller, Edward M},
journal={The Journal of finance},
volume={32},
number={4},
pages={1151--1168},
year={1977},
publisher={JSTOR}
}

@article{jeffreys1946invariant,
title={An invariant form for the prior probability in estimation problems},
author={Jeffreys, Harold},
journal={Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences},
volume={186},
number={1007},
pages={453--461},
year={1946},
publisher={The Royal Society London}
}

@article{blume2018case,
title={A case for incomplete markets},
author={Blume, Lawrence E and Cogley, Timothy and Easley, David A and Sargent, Thomas J and Tsyrennikov, Viktor},
Expand Down Expand Up @@ -1378,6 +1434,16 @@ @article{HarrKreps1978
pages = {323-336}
}

@article{Morris1996,
author = {Stephen Morris},
title = {Speculative Investor Behavior and Learning},
journal = {The Quarterly Journal of Economics},
year = {1996},
volume = {111},
number = {4},
pages = {1111-1133}
}

@article{pal2013,
title = {Fitted value function iteration with probability one contractions},
author = {P{\'a}l, Jen{\H{o}} and Stachurski, John},
Expand Down
1 change: 1 addition & 0 deletions lectures/_toc.yml
Original file line number Diff line number Diff line change
Expand Up @@ -112,6 +112,7 @@ parts:
- file: markov_asset
- file: ge_arrow
- file: harrison_kreps
- file: morris_learn
- caption: Data and Empirics
numbered: true
chapters:
Expand Down
35 changes: 17 additions & 18 deletions lectures/harrison_kreps.md
Original file line number Diff line number Diff line change
Expand Up @@ -3,10 +3,12 @@ jupytext:
text_representation:
extension: .md
format_name: myst
format_version: 0.13
jupytext_version: 1.17.1
kernelspec:
display_name: Python 3
language: python
name: python3
display_name: Python 3 (ipykernel)
language: python
---

(harrison_kreps)=
Expand All @@ -29,10 +31,9 @@ kernelspec:

In addition to what's in Anaconda, this lecture uses following libraries:

```{code-cell} ipython
---
tags: [hide-output]
---
```{code-cell} ipython3
:tags: [hide-output]

!pip install quantecon
```

Expand All @@ -51,7 +52,7 @@ The model features

Let's start with some standard imports:

```{code-cell} ipython
```{code-cell} ipython3
import numpy as np
import quantecon as qe
import scipy.linalg as la
Expand Down Expand Up @@ -131,15 +132,15 @@ But in state $1$, a type $a$ investor is more pessimistic about next period's

The stationary (i.e., invariant) distributions of these two matrices can be calculated as follows:

```{code-cell} python3
```{code-cell} ipython3
qa = np.array([[1/2, 1/2], [2/3, 1/3]])
qb = np.array([[2/3, 1/3], [1/4, 3/4]])
mca = qe.MarkovChain(qa)
mcb = qe.MarkovChain(qb)
mca.stationary_distributions
```

```{code-cell} python3
```{code-cell} ipython3
mcb.stationary_distributions
```

Expand Down Expand Up @@ -270,7 +271,7 @@ The first two rows of the table report $p_a(s)$ and $p_b(s)$.

Here's a function that can be used to compute these values

```{code-cell} python3
```{code-cell} ipython3
def price_single_beliefs(transition, dividend_payoff, β=.75):
"""
Function to Solve Single Beliefs
Expand Down Expand Up @@ -399,7 +400,7 @@ Investors of type $a$ want to sell the asset in state $1$ while investors of typ

Here's code to solve for $\bar p$, $\hat p_a$ and $\hat p_b$ using the iterative method described above

```{code-cell} python3
```{code-cell} ipython3
def price_optimistic_beliefs(transitions, dividend_payoff, β=.75,
max_iter=50000, tol=1e-16):
"""
Expand Down Expand Up @@ -444,8 +445,8 @@ Instead of equation {eq}`hakr2`, the equilibrium price satisfies
\check p(s)
= \beta \min
\left\{
P_a(s,1) \check p(0) + P_a(s,1) ( 1 + \check p(1)) ,\;
P_b(s,1) \check p(0) + P_b(s,1) ( 1 + \check p(1))
P_a(s,0) \check p(0) + P_a(s,1) ( 1 + \check p(1)) ,\;
P_b(s,0) \check p(0) + P_b(s,1) ( 1 + \check p(1))
\right\}
```

Expand All @@ -467,7 +468,7 @@ Constraints on short sales prevent that.

Here's code to solve for $\check p$ using iteration

```{code-cell} python3
```{code-cell} ipython3
def price_pessimistic_beliefs(transitions, dividend_payoff, β=.75,
max_iter=50000, tol=1e-16):
"""
Expand Down Expand Up @@ -512,8 +513,6 @@ Scheinkman extracts insights about the effects of financial regulations on bubbl

He emphasizes how limiting short sales and limiting leverage have opposite effects.

## Exercises

```{exercise-start}
:label: hk_ex1
```
Expand Down Expand Up @@ -570,7 +569,7 @@ We'll use these transition matrices when we present our solution of exercise 1 b
First, we will obtain equilibrium price vectors with homogeneous beliefs, including when all
investors are optimistic or pessimistic.

```{code-cell} python3
```{code-cell} ipython3
qa = np.array([[1/2, 1/2], [2/3, 1/3]]) # Type a transition matrix
qb = np.array([[2/3, 1/3], [1/4, 3/4]]) # Type b transition matrix
# Optimistic investor transition matrix
Expand All @@ -595,7 +594,7 @@ for transition, label in zip(transitions, labels):
We will use the price_optimistic_beliefs function to find the price under
heterogeneous beliefs.

```{code-cell} python3
```{code-cell} ipython3
opt_beliefs = price_optimistic_beliefs([qa, qb], dividendreturn)
labels = ['p_optimistic', 'p_hat_a', 'p_hat_b']

Expand Down
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