diff --git a/lectures/markov_chains_I.md b/lectures/markov_chains_I.md index 40285910..16aed135 100644 --- a/lectures/markov_chains_I.md +++ b/lectures/markov_chains_I.md @@ -107,8 +107,6 @@ From US unemployment data, Hamilton {cite}`Hamilton2005` estimated the followin ``` -+++ - Here there are three **states** * "ng" represents normal growth @@ -294,7 +292,7 @@ Looking at the data, we see that democracies tend to have longer-lasting growth regimes compared to autocracies (as indicated by the lower probability of transitioning from growth to growth in autocracies). -We can also find a higher probability from collapse to growth in democratic regimes +We can also find a higher probability from collapse to growth in democratic regimes. ### Defining Markov chains @@ -411,7 +409,6 @@ def mc_sample_path(P, ψ_0=None, ts_length=1_000): X = np.empty(ts_length, dtype=int) # Convert each row of P into a cdf - n = len(P) P_dist = np.cumsum(P, axis=1) # Convert rows into cdfs # draw initial state, defaulting to 0 @@ -683,7 +680,7 @@ P = np.array([[0.4, 0.6], ψ @ P ``` -Notice that `ψ @ P` is the same as `ψ` +Notice that `ψ @ P` is the same as `ψ`. @@ -772,11 +769,11 @@ For example, we have the following result (strict_stationary)= ```{prf:theorem} Theorem: If there exists an integer $m$ such that all entries of $P^m$ are -strictly positive, with unique stationary distribution $\psi^*$, and +strictly positive, with unique stationary distribution $\psi^*$, then $$ \psi_0 P^t \to \psi^* - \quad \text{as } t \to \infty + \quad \text{ as } t \to \infty $$ ``` @@ -837,8 +834,6 @@ ax.scatter(ψ_star[0], ψ_star[1], ψ_star[2], c='k', s=60) plt.show() ``` -+++ {"user_expressions": [], "tags": []} - Here * $P$ is the stochastic matrix for recession and growth {ref}`considered above `. @@ -1083,8 +1078,6 @@ Solution 1: ``` -+++ - Since the matrix is everywhere positive, there is a unique stationary distribution. Solution 2: