Key Points:

Would you like to vote to ban same-sex marriage, declare a fertilised human egg is a person or decriminalise personal use of marijuana? Welcome to the United States elections on November 4. That's democracy - or is it?

In representative parliamentary democracies like ours, voters elect people to Parliament to make decisions and laws and keep a check on the government on their behalf.

But there is a growing push in parliamentary democracies to second-guess or override the representatives, the MPs. Some argue for voters to decide important issues by referendum. Some argue for citizens' juries and assemblies or Scandinavian-style interest group roundtables to generate consensus on complex issues.

All proposals are live here.

John Key wants you to vote in 2011 whether to keep or amend the mixed-member proportional (MMP) voting system. Steve Baron's Better Democracy organisation wants us to emulate Switzerland's resort to referendums for important decisions - including on international treaties.

The Greens want citizens' assemblies to bring informed non-party common sense to bear on major issues. Last year it persuaded a reluctant Government to set up a non-parliamentary panel to help refine the Electoral Finance Act.

Ecologic's Guy Salmon has studied the Scandinavian systems in the context of environmental issues, the sort for which consensus is needed but is elusive. National's Nick Smith has expressed interest.

All this is far from the 18th-century principle stated by Edmund Burke: that he had been elected to exercise his best judgment on behalf of the nation, not to act as his constituents' delegate.

Our democracy still rests broadly on this principle. Helen Clark's Governments rejected calls for referendums on bills legalising civil unions, banning whacking of children and abolishing legal appeals to the British Privy Council.

Ministers said the issues were either too emotive or too lofty and complex to be entrusted to a popular vote. In short, MPs know best.

Or do they? On sensitive issues some MPs poll constituents and vote accordingly. John Key, in favour of civil unions, voted against after tapping his constituents. Simon Power similarly switched on the whacking bill (though was able to vote for the eventual bipartisan compromise).

In 1911, in the face of a strong temperance movement, MPs instituted a referendum which for nearly eight decades ran alongside each election giving voters the option of an outright ban on alcohol, state control or private enterprise. Individual electorates could, and some did, vote to go "dry". The last three went "wet" in 1999.

In the wake of the 1992 and 1993 referendums which introduced MMP, it is now an unwritten rule that the electoral system may be changed only by referendum.

MPs initiated those referendums. Only in 1994 did voters gain the right to initiate referendums. But these citizens-initiated referendums (CIRs) are "indicative".

They do not bind Parliament and none of the three that have passed has been acted on - on firefighter numbers, on reducing Parliament to 99 MPs and on crime victims and sentences (though tougher laws on crime have been passed).

In the United States, about half the states run "propositions". If enough voters sign a petition an issue goes on the ballot paper at election time, and if a requisite majority votes for it, the legislature must enact it into law.

One of the most famous was proposition 13, which in 1978 cut California's property taxes. This sort of tax cap appeals to some economists and businesspeople here.

The argument for referendums is that the public has no direct means of influencing policy on major issues. Parties claim "mandates" for action from voters in general elections. But voters don't vote for a party's every individual policy.

They may hold their noses on a moral issue but vote for a party on other aspects of its programme.

Professor Elizabeth McLeay of Victoria University, who has studied referendums, says they are "attractive" because they are inclusive, which gives them legitimacy, because MPs sometimes defer to vested interests, because they can be a "second chamber" in a one-chamber system (which New Zealand's is) and because they can prompt more "civic virtue" (involvement in the political sphere).

But McLeay notes that citizens can already form and join pressure groups, petition Parliament and make submissions to select committees, which under MMP do listen more to submitters and make changes to bills accordingly.

"We have a freely accessible system, if voters care to use it." In addition, Governments often consult interest groups and the public on initiatives.

So McLeay argues that there should be five criteria for binding referendums. The question must be unambiguous and easily understood. There must be full information so an informed decision can be made.

There must be constraints so that publicity is even-handed (not as in the richly financed opposition to the 1992 and 1993 MMP referendums).

The criteria must "enhance trust in political institutions" (that is, not undermine Parliament). And "every voter must have a stake in the question being asked" - a referendum should not advance sectional interest (McLeay cites flat tax as an example where that would not be the case).

Do citizens-initiated referendums (CIRs) meet those criteria? The push for them was a reaction to the 1984-90 Labour Government's economic reform radicalism.

The calls for referendums on civil unions, whacking and the Supreme Court came mainly from opponents with strong views. Would referendums in those cases have truly reflected public opinion if fired-up opponents had turned out in droves and laid-back supporters had not?

Some United States "propositions" are bizarre or very technical. Switzerland's cumbersome system denied women the vote until 1971. Moreover, the Swiss are long practised at referendums and New Zealanders aren't.

All of those factors argue for McLeay's caution. And referendums are blunt: they demand a yes-no answer. That can leave the public divided.

Opponents of MMP reckon the 54-46 vote in 1993 was too narrow on a major issue.

So citizens' assemblies and juries are gaining credence as an alternative.

There are many versions but essentially they are composed of citizens, randomly selected so they are representative, who explore an issue over some time and with expert guidance and reach a conclusion. They are in a sense large focus groups inside the political process.

Canada has pioneered this technique, particularly for constitutional or electoral matters, in which MPs have a vested interest. Professor Jonathan Rose, of Queens University in Ontario, says it can tap into the "wisdom of crowds" and is particularly useful to resolve a parliamentary impasse.

Canterbury University academic Therese Arseneau, a Canadian, says people in an assembly or on a jury change their minds on the evidence, while a referendum can entrench rather than resolve divisions.

Green MP Metiria Turei reckons them superior to referendums because those involved can reach a measured, informed decision. However, she thinks they should not be binding but only recommendatory.

The Scandinavian countries have taken a different tack. In various ways, they bring together peak interest groups, officials and politicians to thrash out a consensus over time - sometimes over several years - in which competing interests are reconciled through reciprocal concessions.

The leadership forum set up here to advise on the emissions trading legislation was a pale copy. Had a climate change roundtable been set up in 2000 and been more broadly based, it might have generated a way forward in deeply divisive policy area.

That opportunity was missed. But it may well be taken in future. The growing interest in that and other alternatives indicate democracy is not just elections and Parliament. Like everything, it is in flux.