One of the most important roles of government is to prevent vested interests from rigging the market so as to extract a higher payment from consumers than would be secured in a free market.
This is what economists call "rent-seeking", and in the absence of any more familiar word for this practice, I shall use it here.
Many vested interests succeed in inhibiting this market-oriented role of governments by exercising political or financial pressure to persuade politicians not to interfere with their rent-seeking activities.
In theory, one might expect that democratic politicians would be under such pressure from the electorate - who are, of course, the potential beneficiaries of action to limit such rent-seeking - that they would be wary of succumbing to pressures from such vested interests. But in practice the electorate is often either unaware of or insensitive to such attempted exploitation to put governments under pressure to tackle the activities of rent-seeking vested interests, or to react against failure by the Government to tackle such abuses.
Instead, governments are often more sensitive to pressures from self-interested groups - whose votes or financial support they fear losing - than to the interest of the wider electorate, whose members are not organised to protect or advance their interests. Consequently they are tempted to tolerate rent-seeking, as a result of which democracy often fails to work in favour of the general interest.
To the extent that the perverse influence of vested interests on government derives from the financial support that some of these groups give to political parties, this could - and should - be dealt with by simply banning all such donations and replacing them with additional State financing of parties.
One might expect that a reform of party funding by private interests could be effected by whichever parties benefit least from business financing who should seek to level the playing field by committing themselves to reforming the system when they eventually find themselves in government.
But, although a few years ago public distaste for abuses deriving from business contributions to political parties appeared close to provoking such a reform, the Opposition parties seem to have abandoned the idea of committing themselves to using public office to create a level playing field between parties, thus at the same time eliminating a source of potential abuse.
A complicating factor in this political failure has been that those interested in rent-seeking are not confined to business interests seeking to block competition.
Equally committed to rent-seeking are some trade unions which, in addition to their valuable services in protecting workers from exploitation, often fall into the trap of themselves engaging in rent-seeking - either by seeking to protect non-viable employment, or attempting to secure pay rates above the market level.
(Over 50 years ago, when I was preparing a pay claim for my grade in Aer Lingus, I looked to the ESB as a headline for pay rates because the staff and unions of that monopoly State enterprise were even then famous for their success in securing pay levels above the market level.)
Governments have been notoriously reluctant to take on rent-seeking by public bodies, or by their unionised staffs - and none has been more reluctant than the present Government under its union-oriented Taoiseach, Bertie Ahern.
The extraordinary delay in introducing competition into the Dublin bus system, regardless of the huge problems this has posed for Dublin's citizens, is a striking example of the Taoiseach's reluctance to pursue the public interest when rent-seeking unions oppose change.
Recently the public authorities appear to have come to see privatisation as a means of extricating themselves from the invidious process of taking on trade unions representing workers in public monopolies.
There are, of course, other arguments than that in favour of privatisation. Thus in the past, while governments far too often succumbed to pressures to subsidise or bail out inefficient public enterprises, at the same time they have perversely been reluctant to invest in viable State enterprises, because of pressure to fund competing infrastructural and social investment.
Thus, over the entire 70 years of Aer Lingus's existence as a public enterprise, the cumulative State investment in that company (as distinct from money spent bailing it out when it had become nearly bankrupt), was negligible. At various points in the airline's history this neglect prevented it from expanding.
A problem has, I believe, been that the Department of Finance, rightly concerned about the waste of public resources in propping up failing State enterprises, has often had difficulty in recognising worthwhile projects to expand.
As for rent-seeking by the private sector, politicians have shown limited enthusiasm for tackling this problem. Occasionally governments make a sporadic effort - most recently on the drift-net fishermen's lobby, in which they did not secure the support of the principal Opposition party.
The public authorities have also long been attempting to engage with medical consultants on the contracts for the public health service that entitle them to engage in extensive private practice - an arrangement that creates potential conflicts of interest - but which latest reports suggest may now be allowed to continue in a modified form.
We clearly have a long way to go before our governments take their responsibilities in relation to rent-seeking as seriously as the public interest demands.