economy focused on the lack of data to understand the most basic aspects of the overseas trade. These included the lack of knowledge of demand for goods, the proportion of foreign goods to domestic sent to the Indies, and comparative prices of goods in European markets. Spanish merchants functioned without knowledge of matters in which European merchants were experts. He also commented on the socioeconomic patterns of foreign merchants, whose sons married Spanish women and their sons could operate legally within the restrictive Spanish system, but the most promising of these young men were sent to Genoa to learn the real mechanics of international trade. These foreign enterprises with insider status were a part of extended family enterprises, so that they could operate on a truly international scale. “They were well positioned to exploit colonial markets to the disadvantage of their under-capitalized and poorly informed Spanish competitors whose capital averaged [only] 20,000 pesos.” Foreign merchants did not want to completely undermine the structure of trade, so made loans to Spanish merchant firms to keep them participating in the trade. Other writers Antonio Serra, a Neapolitan (and therefore a subject of the same Catholic Monarchy of the Habsburgs), wrote Breve trattato delle causa che possono far abbondare with the historical and intellectual context of Castilian abitrismo. He attributed the shortage of currency in the Kingdom of Naples to a deficit in the balance of payments, a term that it defines with a complete analysis, rejecting the idea that the monetary shortage could be due to the exchange rate, and proposing export incentives as a solution. It also seems that he formulated a similar concept to the law of diminishing returns for agriculture. Antonio López de Vega ( Heraclitus and Democritus of our century ), considered war the cause of decadence. Francisco Martínez de Mata ( Memorials and Discourses , 1650-1660), was "critical of foreign merchants who left Spain only 'the responsibility of keeping [the colonies] while Spaniards are their miserable servants'." He urged the revival of Spanish manufacturing, the end of foreign tax farmers, and the creation of an investment bank to provide credit to Spanish entrepreneurs. References Further reading Bronner, Fred. "Peruvian Arbitristas Under Viceroy Chinchón". Scripta Hierosolymitana 26(1974): 34-77. Elliott, J.H. "The Decline of Spain" in Spain and Its World, 1500-1700. New Haven: Yale University Press 1989, Stein, Stanley and Barbara H. Stein, Silver, Trade, and War: Spain and