Scottish merchants would gain access to English colonies, markets and raw materials. This would mean that Scots had level competition with European rivals for trade and there would be less poverty in Scotland under Union.
Union with England might help Scotland recover from the failure of the Darien Scheme.
It would give Scots greater standing in Europe. Scottish representatives would be heard by the King in London.
Anti-Jacobites supported Union as it would mean that the Hanoverian succession would be secured.
Scotland would have greater security. England was the most powerful country in Europe so would be less likely to be invaded.
Scotland and England shared similar language, religion and trade traditions.
The Presbyterian Church would be safe as both countries did not want a return to Catholicism.