Commercial Purchase System
Commercial Purchase System Data Processing
The Estimated Commercial Landings Tables and Graphs in this web site are based on summarized data from the Commercial Purchase System
At the beginning of each month, a DFW employee visits each of the dealers on Saipan, Rota and Tinian to collect the previous month's invoices, to resolve problems, and to answer any questions the dealers may have. The invoices are then returned to the office for an initial visual edit during the coding process and entered into the "Purchase" database. After the records are entered, reports are generated to help verify that all data were entered correctly.
After all editing, adjustment, and quality control activities have been completed, monthly and annual summary reports by species are generated. Each monthly report contains a subtotal for the sum of all species for that month. Annual reports contain the total landings for each species and the total recorded landings for all species for the calendar year.
On a quarterly basis, copies of the data are sent to the Honolulu Laboratory, where the data are transferred to the central computer for additional verification before generating summary reports. These reports and databases are then ready for use by qualified WPacFIN participants and summary charts and tables are included in this web site.
Although the Saipan data collection system has been in operation since the mid-1970s, only data collected since 1981 are considered accurate enough to be used.
Annual Percent Coverage Factors
Receipts submitted by all participating dealers on Saipan, Rota and Tinian are adjusted to create the estimated total commercial landings by dividing by an estimated annual percent coverage factor. This factor compensates for non-participating dealers and for casual sales of fish directly to consumers.
A value of 80% was used as an annual percent coverage factor for all years from 1981 to 2003. A value of 55% was used as a percent coverage factor for 2004 to 2006 and 60% was used for 2007 and 2008.