LTXVII-XVIII a. prekyba Joniškyje mažai tirta. Vienas kitas autorius tik epizodiškai paliesdavo šį klausimą. Dažniausiai tiek, kiek tai buvo reikalinga jų nagrinėjamai temai. Jau minėtos studijos autoriai A. Tyla ir A. Miškinis prekybą nagrinėjo tiek, kiek buvo reikalinga parodyti jos įtaką miesto augimui, jo urbanistinei raidai. Nežiūrint to, jų darbas labiausiai susijęs su šio straipsnio tema. Kiti autoriai prekybą nagrinėjo dar mažiau. Šaltinių šiuo klausimu taip pat nėra daug. Yra išlikusios aštuonios XVIII a. Joniškio teismų knygos, kuriose yra duomenų ir apie prekybą. [p. 13].
ENOn the basis of the published and archival sources the development of trade in Joniškis from 1616 when the town obtained the Magdeburg Rights (self-rule) to the partition of the Lithuanian-Polish State in 1795 has been investigated in this report. In the first chapter trade in markets and fairs has been discussed as well as the reguliations and the privileges of the rulers, starting from the privilege of self-rule granted on July 4, 1616, concerning trade in Joniškis. Days of markets and fairs have been analysed according to the granted privileges, their alteration and effect, market. fees, measure system, conflicts between town-dwellers and countryside inhabitants due to the unregulated trade which stimulated illegal commerce in the countryside. Except of the privileges, trade in towns, had been regulated by the resolutions of the inhabitants' assembly the latter being defined in a more detailed and concrete way. They determined sale and purchase rules in markets and duty fees for certain goods. Some acts and records in the judicial books reveal how trade was organized in the Joniškis market places and fairs (mostly concerning the artefacts made by artisans, products of agriculture, and horses). The records of the judicial books display the conflicts in the mar ket places, the means of avoiding them and their solution. Some aspects of the illegal trade with the neighbouring Latvia have also been investigated.In the second chapter of this report the everyday operation of the market places. according to the privileges has been described. Such trade places as shops, pubs, slaugh- terhouses and bakeries were functioning during the period investigated. There were dynasties of owners in Joniškis who owned the same shops over a hundred years. The work of slaughter-houses and the number of shops in the 18th c. were determined as well. On the basis of analogous data about other townships the features of trade have been determined and described. Trade in Joniškis was affected by wars and. epidemics as well as the absence of clearly determined rights of self-rule. There has been one more serious reason presented: Jews had no right to settle there until the middle of the 18th century.