
Define and explore increments as the change in a stochastic process over time, from single-step to multi-step intervals, and highlight their independence for modeling.
Study white noise as a stochastic process where x_t is independently and identically distributed with mean zero. Variance may be nonzero, and the process is stationary with the Markov property.
Explore the random walk defined by x_t = x_{t-1} + e_t, where e_t is white noise, independent increments. It is not stationary; variance grows with time, and drift may occur.
Learn transition probabilities in a Markov chain, denoted p_ij^m(n). Understand transitions between states like healthy, corona, and dead, and crude estimation via N_ij divided by N_i.
Explore a transition matrix in a Markov chain, calculating one-, two-, and three-period probabilities of dying from healthy. Implement the calculations in R using a 3x3 matrix and matrix multiplication.
Stationary probability distributions describe the long-run distribution of people across states in a Markov chain, using the stationary vector pi and the transition matrix to show stable proportions.
Learn the basics of using R for actuaries, part 1, including installing packages, vectors, sequences, repeats, indexing, for and while loops, if statements, functions, and core statistics.
Compare part four to part three to show price frequency lowers taxi frequency, with 17.84% to 12.78% and 5.36 to 4.38 taxis, while cost data govern pods versus taxi choice.
Compare Markov chains and Markov jump processes, contrasting discrete-time transition probabilities with continuous-time transition rates, and explain generator matrices, absorbing states, and diagram representations.
In this course we look at Stochastic Processes, Markov Chains and Markov Jumps
We then work through an impossible exam question that caused the low pass rate in the 2019 sitting.
This question requires you to have R Studio installed on your computer.
Things we cover in this course:
Section 1
Stochastic Process
Stationary Property
Markov Property
White Noise
Increments
Random Walks
Section 2
Markov Chains
Transition Probabilities
Chapman-Kolmogorov Equations
Transition Matrix
Stationary Probability Distributions
Irreducibility
Periodicity
Section3
R Studio Exam Question
Section 4
Markov Jump Process
Transition and Survival Probabilities
Kolmogorov's Forward Differential Equation
Transition Rates
Generator Matrix
Kolmogorov's Backward Differential Equation