Final answer:
Activities not captured by the accounting system and not considered as transactions include sales of used goods, the underground economy, transfer payments, and home-produced goods like meals since they either occurred in a previous period, are difficult to track, do not represent production, or are not sold in the marketplace.
Step-by-step explanation:
The activities that are not captured by the accounting system because they are not considered transactions include a variety of economic events. Firstly, the sales of used goods are excluded from accounting records in terms of Gross Domestic Product (GDP) as they were produced and accounted for in a previous year.
Additionally, the underground economy—which comprises services paid 'under the table' and illegal sales—is not reflected in the accounting system, primarily due to the difficulty in tracking these transactions. Friedrich Schneider's study highlighted that the underground economy could represent a significant 6.6% of the United States GDP. Another excluded activity is transfer payments, such as government payments to individuals, because they are not a representation of production or economic output. Lastly, the production of goods for personal use, such as preparing breakfast at home, is not counted since these goods are not sold in the marketplace and so do not contribute to market transactions.