| Variable | Symbol | Definition of the Variable |
| Integration dummy (dependent variable) | z | Dummy = 1 for firms undertaking vertical integration, 0 otherwise |
| Tobin’s Q | TQ | Ratio of firm value to total assets |
| Advertising intensity | ADV | Ratio of advertisement expense to net sales |
| Net sales | LNS | Natural log of netsales |
| Year dummy | YD | Dummy = 1 when the year of z is same as the year of year dummy, otherwise Dummy = 0 |
| Industry dummy | ID | Dummy = 1 when the industry of z is same as the industry of industry dummy, otherwise Dummy = 0 |