mar. Venice had a salt monopoly for many of these markets. The Salt Office collected 165,000 ducats net of costs in 1464, or around 15% of the entire income of the Venetian state. Decline According to Diego Puga and Daniel Trefler, the Serrata del Maggior Consiglio (which made the parliamentary participation hereditary) led to barriers to participation in the most profitable aspects of long-distance trade. This diminished the ability of those outside of the hereditary aristocracy to participate in political decisions and in economic processes such as the colleganza. This stratification in political and economic power led to a fundamental shift from political openness, economic competition, and social mobility to political closure, extreme economic inequality, and social stratification and stiffness. According to economic historian Jan De Vries, Venice's economic power in the Mediterranean had declined significantly by the start of the 17th century. De Vries attributes this decline to the loss of the spice trade, a declining uncompetitive textile industry, competition in book publishing due to a rejuvenated Catholic Church, the adverse impact of the Thirty Years' War on Venice's key trade partners, and the increasing cost of cotton and silk imports to Venice. Immigration The population of Venice – maybe 85,000 to 100,000 at about 1300 – could only bear these permanent losses, because there was also a permanent influx. This influx was heavily encouraged by Venetian officials, especially after the waves of Black Death after 1348. Specialists like silk weavers from Lucca or mill builders and bakers of the Holy Roman Empire migrated in droves. Consequently, Venice was forced to expand within its narrow territory, so gardens and swamps were largely replaced by dwellings. Large numbers of people also immigrated from Tuscany, especially from Florence, as well as southern Italy, Greece, Croatia and even France. From about 1250 an increasing number of people came from the Holy Roman Empire – Germans, Hungarians or Bohemians – called "tedeschi“. They dwelled in the Fondaco dei Tedeschi and they were helped and controlled by Visdomini del Fondaco. Official brokers or middle-men were the only ones who were allowed to buy and sell the products. Also immigrating to Venice, the Jewish people offered much more and cheaper credit to the Venetians, but most of them lived in Mestre. However, with the foundation of the Ghetto in 1516, the majority of the Jewish people started to live in secluded quarters, locked up at