All this proves is that, contrary to popular impression, economics and business management are separate skills. The macro economy is not just a company writ large. Chief offenders among the big business people saying stupid things about wage rates are the miners. In seeking to explain why the fall in coal and iron ore prices from sky-high to merely unusually high has prompted them to start cancelling projects for new mines, they complain that Australia has become a ''high-cost'' place to do business. In part this is an unjustified whinge about the mining tax; in part it's a complaint about the continuing high dollar. The miners are justified in reminding us that all export and import-competing industries are adversely affected by a high exchange rate, including them. For the most part, however, it's a complaint about the way wage rates for mine and construction workers have shot up in recent years. Remember, the West Australian miners were in the vanguard of those using John Howard's WorkChoices to force their workers on to individual contracts and get rid of (admittedly, often unreasonable) unions. It's been the miners leading the campaign by business and the national dailies to reverse the direction of Fair Work and bring back individual contracts. So, the miners want us to believe it's the Fair Work Australia changes and the power they put back into the hands of the unions that explain the rapid rate at which the miners' wage bill has been growing.

If you believe that, you know nothing about economics, starting with the laws of supply and demand. What we've had in Western Australia - and Queensland - is a host of miners, big and small, desperate to expand their existing mines and build new ones and get the projects finished while world prices stay high. So, you've got a sudden surge in demand for labour in remote and inhospitable parts of the country where few workers live, coming from companies that have never put much effort into training their own young workers. Demand for labour has shot way ahead of supply as miners race their competitors to get their projects under way. What happens in any market when demand runs ahead of supply? The price goes up. One of the things the higher price does is attract resources from other parts of the economy. If there are unions present, they will use their improved bargaining power to extract big pay rises from employers anxious just to get on with it. If there are no unions present, much the same thing happens as employers try to outbid their local rivals and also suck in labour from other states. Only an economic ignoramus could imagine wages wouldn't have risen in the absence of unions.

But there's nothing new about the tactic of trying to make Australian workers believe there's something illegitimate about the high wages they're paid. In the protectionist era it was a favourite tactic of manufacturers demanding higher tariffs on imports. Their argument was that, if workers in Asian sweatshops were getting $2 an hour and ours were getting $15, ours were being overpaid by $13 an hour. If that makes sense to you, go to the bottom of the economics class. The first point is that the cost of labour is just part of the total cost of any product, though it's true that labour costs are the biggest element in the prices of simple, labour-intensive items such as textiles, clothing and footwear. Countries such as Germany and Sweden have very high hourly wage costs, yet manage to hold their own in international markets for sophisticated manufactures. How? By compensating for high wage costs by having much better-trained workers, better capital equipment, longer production runs, smarter managers, higher quality, better service or other non-price selling points. More fundamentally, it's possible but not common for the general level of a country's wages to be too high because the union movement has too much power. A rich country's wage rates are very high - way higher than a poor country's rates - because a country's wage rates invariably reflect that country's material standard of living (income per person).

And, as a general rule, what determines a country's standard of living is the level of (as opposed to the annual rate of improvement in) its labour productivity. How does a country achieve the high level of productivity that eminently justifies the high incomes its people are paid? By investing in good infrastructure, in the education and training of its workers and in the latest capital equipment, then ensuring its business and political leaders are highly capable. One test of its political leaders is whether they let lazy business people and self-centred unions con them into making the country's consumers or taxpayers subsidise the continued existence of businesses unable to find a way to compete on the international market. Twitter: @1RossGittins