ECONOMETRIC MODELING OF INTERREGIONAL LABOR MARKET LINKAGES*

ABSTRACT. This paper presents a statistical procedure for empirically establishing linkages between regional economies. Using Granger's definition of causality and the final prediction error technique for lag-length specification suggested by Hsiao, a linked, multiregional employment model is developed. The forecast performance of the linked model is compared to models which do not include interregional linkages. It is shown that forecast error is reduced by taking into account employment interrelationships between regions.     

The Roman wreck of c. AD 200 at Plemmirio, near Siracusa (Sicily): Interim report

A Roman wreck, named Plemmirio B^[1]i, lies on the rocky talus below the southern cliffs of Capo Murro di Porco, near Costa Bianca del Plemmirio (Penisola della Maddalena), prov. Siracusa, Sicily. The cargo of amphoras and iron bars, relatively well-preserved, is situated between 22 m and 47 m depth. Following brief examinations in 1974–1982, a University of Bristol expedition spent four weeks surveying the site in July-August 1983^[2] This paper presents an interim summary of these campaigns; a comprehensive report will be published after completion of excavations at the site^[3]. The archaeological deposit at Plemmirio B is characterized by concentrations of fragmented amphoras. There is no direct evidence for the structure of the ship, much of which may have disintegrated during the initial wreck process, but study of the artefact distribution suggests a vessel of fairly large capacity. The amphora consignment (which may have numbered no more than 200) comprised cylindrical African containers, 80% of which were form Africana 2A and 20% Africana 1^[4] w. The Africana 2A amphoras had internal resinous linings, and so may have contained a fish product rather than olive oil. Other amphoras exposed on the site were at least one Mauretanian Dressel 30 (Keay type 1) and two possibly intrusive amphoras of unclassified types. Ferrous concretions contained voids (hollow casts) which may once have been about 39 wrought iron bars, of two distinctive shapes. These, and several other concretions of unidentified forms, may represent a consignment of iron originally weighing approximately one tonne. Other finds from the wreck are two cooking pots, a small bowl or cup, a sounding lead, three fragments of tegula rooftiles, and two small stone blocks. One of the cooking pots confirms a date for the wreck based on the amphora association of circa AD 180–250, most likely in the first decade of the 3rd century. The amphora assemblage belongs to an important phase of commerce from North Africa represented by at least 20 known wreck cargoes; however, few of these sites have been scientifically recorded or are as closely dated as Plemmirio B, and the diversity of container types and cargo consignments on this wreck is of particular interest.