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[laffer_adaptive] [lake_model] spelling and check example admonition (#…
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* [laffer_adaptive] update style and spelling

- change 'it reverse' to 'it reverses'
- change the subtitle to lower case to match with the style
- change 'pseudo code' to 'pseudo-code' to match with the title for consistency
- change 'limiting values exists' to 'limiting values exist'

- add hyphen to steady state when using is as adjective for consistency.

* [lake_model] update spelling

- change 'the below graph' to 'the graph below' for better word ordering

- change 'long run growth' to 'long-run growth' for consistency
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longye-tian committed Aug 7, 2024
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28 changes: 14 additions & 14 deletions lectures/laffer_adaptive.md
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Expand Up @@ -33,7 +33,7 @@ that we adopted in lectures {doc}`money_inflation` and lectures {doc}`money_infl
We shall discover that changing our hypothesis about expectations formation in this way will change some our findings and leave others intact. In particular, we shall discover that

* replacing rational expectations with adaptive expectations leaves the two stationary inflation rates unchanged, but that $\ldots$
* it reverse the perverse dynamics by making the **lower** stationary inflation rate the one to which the system typically converges
* it reverses the perverse dynamics by making the **lower** stationary inflation rate the one to which the system typically converges
* a more plausible comparative dynamic outcome emerges in which now inflation can be **reduced** by running **lower** government deficits

These more plausible comparative dynamics underlie the "old time religion" that states that
Expand All @@ -50,7 +50,7 @@ by dropping rational expectations and instead assuming that people form expecta
{cite}`marcet2003recurrent` and {cite}`sargent2009conquest` extended that work and applied it to study recurrent high-inflation episodes in Latin America.
```

## The Model
## The model

Let

Expand Down Expand Up @@ -88,9 +88,9 @@ $$ (eq:adaptex)
where $\delta \in (0,1)$
## Computing An Equilibrium Sequence
## Computing an equilibrium sequence
Equation the expressions for $m_{t+1}$ promided by {eq}`eq:ada_mdemand` and {eq}`eq:ada_msupply2` and use equation {eq}`eq:adaptex` to eliminate $\pi_t^*$ to obtain
Equation the expressions for $m_{t+1}$ provided by {eq}`eq:ada_mdemand` and {eq}`eq:ada_msupply2` and use equation {eq}`eq:adaptex` to eliminate $\pi_t^*$ to obtain
the following equation for $p_t$:
$$
Expand All @@ -99,7 +99,7 @@ $$ (eq:pequation)
**Pseudo-code**
Here is pseudo code for our algorithm.
Here is the pseudo-code for our algorithm.
Starting at time $0$ with initial conditions $(m_0, \pi_{-1}^*, p_{-1})$, for each $t \geq 0$
deploy the following steps in order:
Expand All @@ -111,14 +111,14 @@ deploy the following steps in order:
This completes the algorithm.
## Claims or Conjectures
## Claims or conjectures
It will turn out that
* if they exist, limiting values $\overline \pi$ and $\overline \mu$ will be equal
* if limiting values exists, there are two possible limiting values, one high, one low
* if limiting values exist, there are two possible limiting values, one high, one low
* unlike the outcome in lecture {doc}`money_inflation_nonlinear`, for almost all initial log price levels and expected inflation rates $p_0, \pi_{t}^*$, the limiting $\overline \pi = \overline \mu$ is the **lower** steady state value
Expand All @@ -128,7 +128,7 @@ It will turn out that
* the preceding equation for $p_0$ comes from $m_1 - p_0 = - \alpha \bar \pi$
## Limiting Values of Inflation Rate
## Limiting values of inflation rate
As in our earlier lecture {doc}`money_inflation_nonlinear`, we can compute the two prospective limiting values for $\bar \pi$ by studying the steady-state Laffer curve.
Expand Down Expand Up @@ -213,15 +213,15 @@ print(f'The two steady state of π are: {π_l, π_u}')
We find two steady state $\bar \pi$ values
## Steady State Laffer Curve
## Steady-state Laffer curve
The following figure plots the steady state Laffer curve together with the two stationary inflation rates.
The following figure plots the steady-state Laffer curve together with the two stationary inflation rates.
```{code-cell} ipython3
---
mystnb:
figure:
caption: Seigniorage as function of steady state inflation. The dashed brown lines
caption: Seigniorage as function of steady-state inflation. The dashed brown lines
indicate $\pi_l$ and $\pi_u$.
name: laffer_curve_adaptive
width: 500px
Expand Down Expand Up @@ -258,11 +258,11 @@ def plot_laffer(model, πs):
plot_laffer(model, (π_l, π_u))
```
## Associated Initial Price Levels
## Associated initial price levels
Now that we have our hands on the two possible steady states, we can compute two initial log price levels $p_{-1}$, which as initial conditions, imply that $\pi_t = \bar \pi $ for all $t \geq 0$.
In particular, to initiate a fixed point of the dynamic Laffer curve dynamics we set
In particular, to initiate a fixed point of the dynamic Laffer curve dynamics, we set
$$
p_{-1} = m_0 + \alpha \pi^*
Expand Down Expand Up @@ -348,7 +348,7 @@ eq_g = lambda x: np.exp(-model.α * x) - np.exp(-(1 + model.α) * x)
print('eq_g == g:', np.isclose(eq_g(m_seq[-1] - m_seq[-2]), model.g))
```
## Slippery Side of Laffer Curve Dynamics
## Slippery side of Laffer curve dynamics
We are now equipped to compute time series starting from different $p_{-1}, \pi_{-1}^*$ settings, analogous to those in this lecture {doc}`money_inflation` and this lecture {doc}`money_inflation_nonlinear`.
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4 changes: 2 additions & 2 deletions lectures/lake_model.md
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Expand Up @@ -36,7 +36,7 @@ The "flows" between the two lakes are as follows:
3. employed workers separate from their jobs at rate $\alpha$.
4. unemployed workers find jobs at rate $\lambda$.

The below graph illustrates the lake model.
The graph below illustrates the lake model.

```{figure} /_static/lecture_specific/lake_model/lake_model_worker.png
:name: lake_model_graphviz
Expand Down Expand Up @@ -216,7 +216,7 @@ Moreover, the times series of unemployment and employment seems to grow at some

Since by intuition if we consider unemployment pool and employment pool as a closed system, the growth should be similar to the labor force.

We next ask whether the long run growth rates of $e_t$ and $u_t$
We next ask whether the long-run growth rates of $e_t$ and $u_t$
also dominated by $1+b-d$ as labor force.

The answer will be clearer if we appeal to {ref}`Perron-Frobenius theorem<perron-frobe>`.
Expand Down

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