Since Business Studies and Economics are separate subjects, there are not entire topics that overlap between them. However, there are definitely specific concepts that are explored in both subjects, especially in the HSC course. Examples of such concepts include:
- Exchange rates - In Business Studies, exchange rates are explored in the Finance topic of the HSC course. In Economics, exchange rates are explored in the "Australia’s Place in the Global Economy" topic of the HSC course.
- Concepts such as minimum employment standards, minimum wages, awards, enterprise agreements, employment contracts, and dispute resolution - In Business Studies, these concepts are explored in the Human Resources topic of the HSC course. In Economics, these concepts are explored in the "Economic Policies and Management" of the HSC course.
Both subjects are essentially content-heavy and require both short and long responses, including reports and essays. They are also both characterised by the need to know information that extends beyond the content. In Business Studies, students learn and incorporate real-life and hypothetical business case studies into their responses (primarily Section IV). In Economics, students learn and incorporate relevant statistics (as well as other elements) into their Section IV responses.
In terms of the workload, while it will be significant, numerous students take both subjects and achieve favourable results in them. This means that, as long as you regularly study and thoroughly prepare for your assessment tasks/exams, you will be able to perform at a high standard in both subjects.
I hope this helps!