Qmod: A Python class implementing the Abel-Hayashi "Marginal Q" model of investment.

This implementation follows Professor Christopher D. Carroll's lecture notes.

📑 New here? See INDEX.md for a complete guide to repository contents and how to accomplish common tasks.

Installation

Requirements: Python 3.8-3.10 and uv

Linux/macOS:

git clone https://github.com/llorracc/Q-Investment.git
cd Q-Investment
./INSTALL.sh
source .venv/bin/activate

Windows (PowerShell):

git clone https://github.com/llorracc/Q-Investment.git
cd Q-Investment
.\INSTALL.ps1
.venv\Scripts\Activate.ps1

Windows (Command Prompt):

git clone https://github.com/llorracc/Q-Investment.git
cd Q-Investment
INSTALL.bat
.venv\Scripts\activate

See INSTALLATION.md for troubleshooting.

1. Qmod

The Qmod folder includes a file defining the Qmod Python class, which represents a Q-model of capital investment. The Qmod class' current functions include:

• Solution of the model, obtaining its policy rule.
• Drawing of the model's phase diagram.
• Simulation of the model's dynamics starting from a given level of capital.

2. Dolo

The Dolo folder implements the model using Dolo.

3. Examples

Current examples include:

• Qmod-basic-features: illustrates how to use Qmod and its main functions.
• Dolo-simulations: uses Dolo to conduct more complicated simulation exercises that could not be easily achieved using Qmod.
• Structural-changes-Qmod-Dolo: solves the dynamic exercises in Professor Christopher D. Carroll's lecture notes using both Qmod and Dolo.