Is direct democracy effective?

People are more likely to respect and follow decisions if they have been made by the whole population. It gives the law legitimacy.
This is especially important in places like Northern Ireland in 1998 where they needed strong support for the Good Friday Agreement. 70% YES was deemed enough.
It prevents government from making unpopular decisions. Shown by the strong NO vote in the 2004 North-East England regional government referendum.
Encourages participation and educates the public on key issues.
Prevents power from being concentrated in hands of the elite.
Representatives are held accountable for actions at next election.

Some issues are too complex for people to understand.
For example, had the Government held a referendum on whether they should ratify the EU bill on a financial transaction tax in 2011, not many of the public would have been able to make an informed and educated decision on the matter.
Many people based their vote in the EU referendum in 2016 on the claim that £350m was sent to the EU every week and that this could instead be spent on the NHS, however, it quickly became apparent that this redirection would be unlikely.

Having DD in a representative system undermines the role of reps as it gives the public the responsibility to pass important decisions.
Select Committees have expertise and Lords.