A large international company is trying to increase sales figures which have declined due to the COVID-19 pandemic. The Chief Executive Officer thinks that offering bonuses to their staff will help increase sales figures, but before they implement the bonus scheme, they decide to undertake a study to see if it would be effective. They have offices across Germany, France, and Australia, which vary in size [number of employees], type of location [rural or metropolitan] and staff demographics [gender and age]. They randomly select 20 offices from each country to participate in the study. The offices are then randomly divided into two groups: an experimental group and a control group. Each group contains 10 offices from each country.
All staff in the offices participating in the study are emailed and given a list of possible strategies they might use to increase sales. The staff in the experimental group are also notified that they will receive a bonus if the office sales performance improves over the next six months. The staff at the offices in the control group are not informed about the bonus scheme. The CEO believes that the companies which are aware of the bonus scheme will perform better.
The staff of the participating companies are notified that their sales figures will be closely monitored over the next six months. At the beginning of the study the company Chairman visits all companies in the experimental group and gives the staff a pep talk about the company valuing their efforts to increase sales. The amount of sales for each group of offices are recorded at the end of the study for comparison purposes.
What is the independent variable in this study?