not an essential element of the system, it does not need to be included in the database. Instead, AR values are derived from the difference between sales to customers and the cash received in payment of sales.
Events
Economic events are phenomena that affect changes in resources. They can result from activities such as production, exchange, consumption, and distribution. Economic events are the critical information elements of the accounting system and should be captured in a highly detailed form to provide a rich database.
Agents
Economic agents are individuals and departments that participate in an economic event. They are parties both inside and outside the organization with discretionary power to use or dispose of economic resources. Examples of agents include sales clerks, production workers, shipping clerks, customers, and vendors.
The REA model requires that accounting phenomena be characterized in a manner consistent with the development of multiple user views. Business data must not be preformatted or artificially constrained and should reflect all relevant aspects of the underlying economic events. As such, REA procedures and databases are structured around events rather than accounting artifacts such as journals, ledgers, charts of accounts, and double-entry accounting. Under the REA model, business organizations prepare financial statements directly from the event database. The following sales and cash receipts events for a hypotheti- cal retailer can be used to illustrate the inherent differences between classic and REA accounting:
Sept. 1: Sold 5 units of product X 21 @ $30 per unit and 10 units of product Y33 @ $20 per unit to customer Smith (Total sale ¼ $350). The unit cost of the inventory is $16 and $12, respectively (Total CGS ¼ $200).
Sept. 30: Received $200 cash from customer Smith on account, check number 451.
In flat-file or non-REA database systems, the two events would be recorded in a set of classic accounts like those shown in Figure 1-14. This involves summarizing the events to accommodate the account structure. However, the details of the transactions are not captured under this approach.
An REA accounting system would capture these transactions in a series of relational database tables that emphasize events rather than accounts. This is illustrated in Figure 1-15. Each table deals with a