| Symbol | Variable |
|--------|--------------------------------------|
| $p$ | The price in US dollars. |
| $x_{j}^{\mathrm{Feat}}$ | Dummy variable for whether the newspaper advertisement was shown to the customer. |
| $x_{j}^{\mathrm{Hiland}}$ | Dummy variable for the "Highland" brand. |
| $x_{j}^{\mathrm{Weight}}$ | Dummy variable for the "Weight Watchers" brand. |
| $x_{j}^{\mathrm{Yoplait}}$ | Dummy variable for the "Yoplait" brand. |