# Modeling Shocks in COVID 19

An Introduction to Stochastic Differential Equations

In the Quantitative Economics with Julia book, we have added two new lectures.

1. Modeling COVID 19 with Differential Equations
• In this lecture, dynamics are modeled using a standard SEIR (Susceptible-Exposed-Infected-Removed) model of disease spread, represented as a system of ordinary differential equations where the number of agents is large and there are no exogenous stochastic shocks.
1. Modeling Shocks in COVID 19 with Stochastic Differential Equations
• In this lecture, we extend the model to include shocks to the $R_0$ and the mortality rates. Stochastic Differential Equations (SDE) coupled with features in SciML such as Parallel Ensembles provide a rich environment to experiment with non-deterministic models.