• Typically, you will describe your model in a formula, and an accompanying text.
• Remember that you are likely not the first person to use a particular research method, so seek inspiration from published work in good journals about “best practices” of writing up a method (usually, other theses are not good examples - it’s much safer to rely on published work!)
• When writing down your model, please pay attention to use the correct sub indexes (e.g., i for consumers, j for categories, t for time, etc.; not everything will be ijt)

A few examples

Market share attraction model

Source: Hannes Datta, Kusum L. Ailawadi, and Harald J. van Heerde (2017), How Well Does Consumer-Based Brand Equity Align with Sales-Based Brand Equity and Marketing-Mix Response? Journal of Marketing: May 2017, Vol. 81, No. 3, pp. 1-20.