You wrote (with James Medoff) what remains the most-cited book on U.S. unions, What Do Unions Do? Please tell us about your seminal work.

Prior to our work, there was a shortage of evidence available on union effects. Newly available computerised data changed that. In conjunction with other social scientists, we were able to provide a more complete picture of how unions impact society.

The book looked at unions from two perspectives: first, what we called the monopoly face of union – unions acting as raisers of benefits for their members – and second, the voice face of unions, or how unions represented labour in the workplace and in the body politic, giving voice to people who otherwise wouldn’t have had much say. I think, in the long run, this is the stronger and more important face of unions.

So what do unions do?

The first thing unions do is to raise wages for working people, and that obviously benefits the working people. They also increase the kind of benefits that workers want. So, if workers want pensions, the unions negotiate for that. If workers want maternity leave, that’s what they bargain for. If workers want to have better insurance and are willing to give up some wages to get it, unions help them. Unions change the pattern of compensation towards greater benefits.

Because unions make working life better for workers, they lower turnover in unionised workplaces. Employers with unions traditionally have workers who stay longer and contribute to raising the productivity of the enterprise. Employers also get more credible information about what workers really want in the workplace, because the union representatives are democratically elected and they really speak for the workers. So a good, functioning union is a real positive. Of course, not all unions function well. But our evidence, and the evidence people generated twenty years later, demonstrated that, on net, unions are a positive force in the economy.

How are public sector unions different?

Public sector unions are different in an interesting way. Private sector unions can do very little to raise the demand for their services. But public sector unions can try to convince voters that we need more police and better education. By politicking, they can help public sector employers raise the funds to provide more and better public services. They have that unique attribute.

You’ve chosen What Do Unions Do?: A Twenty-Year Perspective as one of your five books. This volume is composed of eighteen papers about your own work. Please explain how this book bolstered and challenged what you first published in 1984.

When the papers were given at a set of symposia, and published in economics journals, I was very nervous – the most nervous I’ve ever been in my academic life. A fair number of the authors were conservative economists who looked at unions through an unfavorable lens, and I thought, if I had made a mistake, they were sure going to find it.

So here were a bunch of people who looked at unions quite sceptically – and they actually found that almost everything we had uncovered was correct. In the end, I felt very happy that all economists could come to agreement about what unions do – at least all economists who actually looked at the evidence.

Your work seems greatly influenced by that of economist Albert O Hirschman. Can you please expound on the theory put forth in Hirschman’s treatise, Exit, Voice, and Loyalty, and explain how you applied it to unions?

Albert Hirschman is one of the most creative thinkers we have in economics. Exit, Voice, and Loyalty was picked by the Times Literary Supplement as one of the most influential books of the last century.

They key idea is that when things are going wrong in democratic societies and market economies, people have two options: exit and voice. Now, what did Hirschman mean by exit and voice? Say you are in a restaurant and your soup is too salty. One option is too storm out. That’s exit. The other option is to call the waiter over and say, ‘Please bring the soup back and ask the chef to make it less salty.’ That’s voice.

His book inspired me to look at unions through somewhat different eyes than most economists. People too often think that workers have only one choice in the competitive market: if you don’t like your job, get another. But there is another choice – you can go to the employer, individually or as a group, and say, ‘let’s change what’s not working’. That’s what unions do.

This simple notion of voice runs through Hirschman’s work. Voice is what democracy is all about. When we don’t like how things are going in America, we don’t exit or expatriate. We vote – we voice our concerns to our elected representatives; we try to effect change to make our country better.

I took the key insight of Hirschman’s analysis and applied it to unions, pointing out that unions give workers a mechanism for voice as a group. They help resolve workplace grievances; bring helpful suggestions to the attention of management; and lower turnover, which benefits firms. These hypotheses were strongly backed up by the all the data we and other people have looked at. Giving voice to workers is one of the key benefits that unions bring, to society, to the economy and to the individual firms where they are organised. There is one other element. Organised labour represents workers’ voices in our broader democracy. Of course, when they support one party, the other party doesn’t like them too much. I think that’s what we are seeing now.

Your next recommendation is Industrial Relations Systems, by John T.