With just nine days to go, there’s finally a sense that the public is starting to take some interest in the Victorian state election. A very respectable crowd showed up at Melbourne University on Monday night to hear the campaign discussed by six distinguished panelists — four journalists and two political operators.

Being mostly media people, it’s not surprising that a lot of their discussion focused on the media. For example, Ian Hanke, a prominent consultant in the Liberal camp, drew attention to the fact that voters are increasingly getting their information from places like social media, where politicians can address them directly, and less from traditional media.

This, of course, elides the difference between reporting and spin — there’s a difference (or at least there should be) between information that’s been filtered by a media organ that can sort truth from falsehood and “information” provided directly by politicians in their own causes.

But this is one of those place where media and politicians have a common interest. The politicians don’t want to admit that their product is spin, and the media don’t want to admit that the change has had very little effect because for years they’ve been doing so little actual reporting they’ve mostly been retailing spin themselves.

There was also much talk about the merits of the parties’ TV advertising and questions about whether negative campaigning had started too late or was getting people’s attention at just the right time. One questioner from the floor tried to tell the panel that voters were turned off by negative advertising and wanted constructive engagement on the issues, but the panelists weren’t buying the idea.

This immediately reminded me of a fascinating piece of reading the other day from the American website Vox. In it David Broockman and Joshua Kalla from the Political Science department at the University of California Berkeley review the literature that shows personal contact with voters — basically doorknocking — to be much more effective than any sort of TV advertising, and the curious failure of political parties to act on these findings.

As Broockman and Kalla put it:

“[I]mpersonal methods have consistently failed to produce cost-effective results, no matter how you slice the data or which populations researchers examine … Even if TV ads provide fodder for much punditry or look impressive in a focus group, there’s not much reason to believe they have lasting impacts on voters’ views or behavior.”

A caveat, of course, in that this is American research, conducted under a different political system to ours: many of the studies, for example, measure effectiveness by looking at turnout, which is not much of an issue under compulsory voting. But there’s no particular reason to think that the reactions of Australian voters are radically different.

Pundits usually say of TV advertising (especially negative advertising) that it must be effective because otherwise parties wouldn’t do it. But Broockman and Kalla offer a few explanations for why parties might persevere with methods that have been shown to be less effective.

One is that assembling a network of canvassers is hard, whereas writing a cheque to an advertising agency is easy. Another is that declining social capital has reduced the availability of volunteers to conduct door-to-door campaigns. A third, “more cynical possibility” is that campaign consultants have a vested interest in recommending TV ads because they take a commission on them.

I don’t know if any consultants in Australia are remunerated that way, but the relationship between the political and media industries is so cosy that it’s really not necessary to assume anything so direct.

Personnel frequently move back and forth; a consultant who told his party that most media advertising was a waste of money would find his future career options somewhat restricted.

Moreover, parties themselves are desperate to secure media goodwill in the shape of favorable news coverage. A cut in the advertising budget is unlikely to help their cause. And a nice showy TV campaign strokes the egos of all involved, much as it does with corporate advertising.

I also suspect that parties are resistant to the idea of large-scale grassroots campaigns for reasons other than cost or difficulty. A grassroots campaign means an energised and empowered membership base, but party hierarchies on both sides seem to have decided that active members are more trouble than they are worth. Having the consultants and their focus groups run the show is much better for the party administrator who is looking for a quiet life.

So in a world of declining revenues for old media across the board, political advertising looks like being one thing they can continue to rely on.