Saturday, July 12, 2014

How economists changed their tune on minimum wages

When the Fair Work Commission announced a 3 per cent increase in the national minimum wage to more than $640 a week - or almost $16.90 an hour - from last week, employers hinted it would lead to fewer people getting jobs and maybe some people losing theirs.

And to many who've studied economics - even many professional economists - that seems likely. If the government is pushing the minimum wage above the level that would be set by the market - the "market-clearing wage" - then employers will be less willing to employ people at that rate.

That's because market forces set the market rate at an unskilled worker's "marginal product" - the value to the employer of the worker's labour.

Almost common sense, really. Except that such a conclusion is based on a host of assumptions, many of which rarely hold in the real world. And over the past 20 years, academic economists have done many empirical studies showing that's not how minimum wages work in practice. They've also developed more sophisticated theories that better fit the empirical facts. It's all explained in the June issue of the ACTU's Economic Bulletin.

As a result, there's been a big swing in academic thinking on the question of the minimum wage. Last year, researchers at the University of Chicago asked a panel of economists from top US universities whether they agreed with the statement that "the distortionary costs of raising the federal minimum wage to $US9 per hour and indexing it to inflation are sufficiently small compared with the benefits to low-skilled workers who can find employment that this would be a desirable policy".

Fully 62 per cent agreed and 16 per cent disagreed, leaving 22 per cent uncertain.

Earlier this year, more than 600 US economists - including seven Nobel laureates - signed an open letter to Congress advocating a $US10.10 minimum wage. They said that, because of important developments in the academic literature, "the weight of evidence now [shows] that increases in the minimum wage have had little or no negative effect on the employment of minimum-wage workers".

The first such study, published by David Card and Alan Krueger in 1994, compared fast food employment in New Jersey and Pennsylvania after one state raised its minimum wage and the other didn't. They did not find a significant effect on employment.

Since then, many similar US "natural experiments" have been studied and have reached similar findings. In Britain, the Low Pay Commission has commissioned more than 130 pieces of research, with the great majority finding that minimum wages boost workers' pay but don't harm employment.

There's been less research in Australia, but one study by economists at the Australian National University, Alison Booth and Pamela Katic, suggests that the facts in Australia seem to fit the "dynamic monopsony" model of wage-fixing.

Under the simple textbook, "perfect competition" model of the market for labour, individual firms face a horizontal supply curve: each firm is so small that its demand for labour has no effect on the price of labour. It can buy as much labour as it needs at an unchanged price.

In the dynamic monopsony model, however, each firm faces an upward-sloping labour supply curve. This is because more realistic assumptions recognise the existence of "imperfections" or, more specifically, "frictions".

Such as? Workers may not have perfect information about all the alternative jobs they could take and this could make them cautious about moving. Searching for a job may involve costs in time or money. Workers and jobs may be mismatched geographically, so changing jobs may involve greater transport costs. Workers - being humans rather than inanimate commodities - may not have identical preferences about the jobs available.

In other words, there are practical reasons why it takes a lot for a worker to want to leave their job.

These frictions, or "transaction costs", are assumed away in the simple model. But their existence can result in employers having market power, which they can take advantage of to pay workers less than the value of what they produce (their marginal product).
Economists call such power "monopsony" power. Just as a monopolist is a single seller, so a monopsonist is a single buyer. But don't take that word too literally. An employer with monopsony power doesn't need to be a monopolist in the market for its product (the "product" market), nor the sole buyer of labour in the region or the industry.
"A single employer in a market with many employers can have monopsonistic power if workers bear costs of job search," the article continues. In other words, it possesses a degree of monopsony power.

The point is, if a firm is facing an upward-sloping labour supply curve and wants to hire more workers, it may need to pay a higher wage than it is paying its existing workers. So, if it goes ahead with hiring, it will need to increase the wage rates of its existing workers.

And this means the firm's profit-maximising level of employment and wages will both be lower than they would be under perfect competition.

In such a model, if the minimum wage rate is set at or below the marginal product of labour, this won't cause employment to fall and may cause it to rise. Monopsonistic models don't have an unambiguous prediction for the employment effect of a minimum wage.

A paper by Bhaskar, Manning and To, published in the Journal of Economic Perspectives in 2002, concluded that "a minimum wage set moderately above the market wage may have a positive effect or a negative effect on employment, but the size of this effect will generally be small".

It will be interesting to see how long it takes those many Australian economists who don't specialise in studying the labour market to catch up with this change in their profession's thinking.