Sunday 20 June 2010


The football World Cup in South Africa has been going on for barely a week and it’s already generated more than its fair share of controversy. The players don’t like the ball because when they kick it, there’s no way telling where it will end up going (strangely enough, that is exactly what happens every time I play football too). And even if they could control the ball, they can’t concentrate on the game because of the constant noise of thousands of vuvuzelas. And then there is the woman who turned out to be a man… but hang on, that was a different competition.

So what is an economist’s view of football? Let’s start with the vuvuzela-blowing spectators. Cheering your own team and booing the opposing team gives you pleasure and makes you bond with your fellow spectators. It is also thought to give an important moral boost to the players, this is referred to as the home advantage: a team is more likely to win if they are playing at home rather than away. At the World Cup, South Africa would therefore enjoy an obvious advantage. Similarly, any country with a larger number of supporters than the opposing team would have an advantage. The North Korean team, most notably, cannot count on too many vuvuzelas cheering them.

But is it really the players who are subject to the home advantage? A recent paper by Mikael Priks and Per Pettersson-Lindbom of Stockholm University (Behavior under Social Pressure: Empty Italian Stadiums and Referee Bias, Economic Letters, 2010) suggests it is in fact the referees who are influenced by noisy spectators. How do you go about testing this? The answer is simple: let some games be played without spectators (treatment group) and compare the actions of the referees in those games with those played with spectators (control group). Of course, few clubs would accept this: they would loose both the home advantage and revenue from ticket sales. Instead, Priks and Pettersson-Lindbom managed to find what is referred to as a natural experiment. In 2007, the Italian government responded to an incident of hooligan violence by banning spectators from games at stadiums that did not meet minimum safety standards. As a result, a small fraction of games in Southern Italy were played without any spectators. Using this variation, they found that the referees behaved differently depending on whether spectators are present or not. In particular, the away team is punished more harshly (in terms of recognizing fouls and issuing yellow or red cards) when spectators are present. In contrast, they found no difference in the player’s behavior. In other words, the home bias is important but not because it boosts the home team’s performance. Instead, Priks and Pettersson-Lindbom argue, the referees are susceptible to social pressure from the crowds. So those complaining about the noise of the vuvuzelas are right and wrong at the same time. The vuvuzelas are affecting the outcome of the game but not because they distract the players or affect their concentration. Such an effect would presumably affect both teams equally and therefore it would be neutral with respect to the game‘s outcome. The vuvuzela effect is much more sinister: it can potentially bias the decisions of the referees in favor of the team with more numerous and more vocal supporters.

Another important complaint with this year’s World Cup has been the low number of goals scored in most games. This lowers the spectators’ enjoyment and leads to a relatively large number of games ending up in a tie. Some commentators attribute this to the already-mentioned balls used this year, which the players supposedly have a hard time controlling. Another explanation is that this is a an outcome of the players utility maximization. To score goals, players need to play aggressively, which is costly: it requires physical effort, increases the risk of injury and you risk spreading yourself too thin and thus giving the other team an advantage if they get possession of the ball. As a result, both teams have an incentive to play cautiously and defensively. In an attempt to alter this incentive, the payoff to winning has beeny increased from 2 points to 3 (a draw brings 1 point to each team) but that does not seem to have done the trick. A recent paper by Juan Carrillo (“Penalty Shoot-outs: Before or after Extra-time?” Journal of Sports Economics, 2007) suggested a further rule change: penalty shoot-outs should take place before rather than after extra time, with their outcome binding only if extra time ends in a draw again. This increases the stakes and alters the incentives of both teams: rather than both playing cautiously, the team that lost the penalty shoot-out now has an incentive to play an aggressive game while the other team needs to be defensive. This prediction, however, is only theoretical: would it also hold in practice? And how is it going to affect the outcome of the game? When one team plays more aggressively while the other team becomes more defensive, it is not a-priori clear whether this should leads to the aggressive team scoring more goals or the defensive team warding off such goals.

Lian Lenten, Jan Libich (La Trobe University) and Petr Stehlik (University of Western Bohemia) think they found a way to test this (“Penalties Before or after Extra-time? An Empirical Assessment of Footballers‘ Incentives,” manuscript). They point out that the proposed scheme is similar to the away rule whereby, if extra time ends in a draw, the team which scored more goals in away games wins. Scoring a goal during the first few minutes of extra time changes the incentives of the two teams in the same way. In either case, one team – the one with the lower number of away goals or the one which conceded a goal at the beginning of extra time – has to play more aggressively while the other team needs to defend their advantage. They use data from thousands of games played in 2007-9 and find that the away rule or a goal during the first five minutes of extra time indeed increases the probability of scoring in extra time – by approximately 45-60%. Economics is the study of incentives. This research shows that by moving the penalty shoot-outs forward – and thus holding them more often – it is possible to alter the underlying incentives and indeed the game itself in such a way that the outcomes of penalty shoot-outs decide fewer games. The World Cup organizers should perhaps take a leaf out of economists’ book. The result will be a more interesting and more enjoyable game.

Yes, Prime Minister

The highlight of the election campaign for me was the ‘bigoted woman’ remark made by Gordon Brown just a few days before the election. My initial reaction was that Ms Duffy, the woman in question, deserved it because she complained about Eastern European immigrants coming to the UK – and hence she showed herself indeed to be a bigot. But on second thought, things are less clear cut and this incident raises several intriguing questions.

The first question is: did this woman deserve to be called bigoted? The answer is no. A bigot is someone who dislikes or despises foreigners or people of a different race, religion, etc. Ms Duffy’s complaint about Eastern European immigrants, instead, reflects plain and simple rational self-interested utility-maximizing behavior. The immigration from the new member countries of the EU was massive by any account – in the range of 1 million since 2004. The vast majority of Eastern European immigrants went for low-skilled low-paid jobs. By doing so, they directly threaten the employment prospects and wages of low skilled low paid UK workers (for more on that, see below). Ms Duffy is retired and therefore she would be little affected herself but many of the people she presumably cares about – her neighbours, friends and family – may well be affected.

Next, did the prime minister address her concerns well? Following her complaint (‘all these Eastern Europeans coming in, where are they flocking from?’) Brown replied: ‘A million people come in from Europe, but a million British people have gone into Europe.’ In other words, he says that British workers benefit from the free mobility of labor within the EU too. That is true enough, except it is not necessarily the same kind of workers. You don’t hear many stories about British plumbers or construction workers moving to France, Spain or indeed Poland. So Brown was really telling Ms Duffy that the hardship experienced by her children or neighbours is compensated by the gains enjoyed by British consultants, bankers and managers moving overseas. As the prime minister, he should indeed care about the wellbeing of all citizens, regardless of their social class or bank balance. But he cannot expect Ms Duffy to feel the same.

Now, is immigration good or bad for the UK labor market? The answer is that immigration can be good or bad, depending on who you ask. Recent work of Christian Dustmann of UCL (with various co-authors) sheds light on this question specifically in the UK context (in particular, his articles in the Economic Journal in 2005, with Fabbri and Preston, and in the Oxford Review of Economic Policy in 2008, with Glitz and Frattini). Let’s consider first what the theory says. Most people intuitively think of a standard demand-supply framework. If the number of workers goes up because of immigration, the supply curve shifts out and as a result the price of labor, or wage, falls. Or, if the wage is fixed, for instance because of trade-union pressure or minimum-wage rules, then the result is involuntary unemployment. However, this framework assumes autarky – no trade with the rest of the world and no mobility of the other factor of production – capital. Once we consider an open economy, things change. If the structure of immigration is the same as that of the native population, then immigration has no long-term effect. Increased supply of labor initially exerts downward pressure on wages, this increases firms’ profits and more firms enter the market. In other words, the economy adjusts to immigration by importing capital.

Most of the Eastern European immigrants, however, are low skilled. Hence, they are substitutes for low-skilled workers like Ms Duffy. In contrast, they are likely to be complementary with high-skilled workers. In this case, the labor-market impact of immigration becomes varied: wages of low-skilled workers go down while those of their high-skilled counterparts go up. Overall, the average effect on wages is close to zero and is in fact even likely to be positive, leading to the so-called immigration surplus.

What about empirical evidence? Dustmann and his co-authors look at the wage impact of immigration along the entire distribution of UK natives’ wages. They find that if immigration increases by one percent, the average wage goes up by 0.35 percent. This increase, however, is not universally shared by all. The effect is negative for those with the lowest wages, positive for those with intermediate wages (median wages increases by 0.6 percent) but becomes insignificant again for those with the highest wages. This pattern nicely mirrors the relative distribution of immigrants to the UK: most are low-skilled but there are also quite a few very high-skilled ones. Hence, immigration is good for this country, on average, but has distributionary implications: it produces both winners and losers.

And finally, is Ms Duffy an exception in her dislike of immigrants? As I explained above, her remarks make economic sense: low skilled workers should be opposed to immigration while high skilled workers should be in favor. Or, to be more precise, this pattern should prevail in the UK and other developed industrialized countries in which skilled labor is relatively abundant. Such countries should import the relatively scarce factor of production – unskilled labor – and export the abundant factors – capital and skilled labor (the opposite should hold in less developed countries where low-skilled labor is abundant and low-skilled workers should be therefore in favor of unrestricted migration). This is again the reason why Brown’s argument about Brits moving to other European countries doesn’t hold water with Ms Duffy. It turns out that Ms Duffy’s view of immigration indeed holds more generally. This is confirmed by recent work by Kevin O’Rourke and Richard Sinnott (European Journal of Political Economy 2006) and Anna Maria Mayda (Review of Economics and Statistics 2006). They look at preferences over immigration expressed by respondents in large multi-country opinion surveys and find, as the theory suggests, that high-skilled individuals are more likely to be in favor of immigration in rich countries than in poor countries. Hence, Ms Duffy is not a bigot, she’s part of the mainstream.

Some food for thought instead of a conclusion: if immigration hurts the low-skilled and the less well-off and benefits the high-skilled and those relatively well-off, and given that Conservatives traditionally draw their support from among the well-off while Labour seeks to represent the working class, why are the Conservatives and not Labour opposed to immigration?

[Originally published in Economics and Finance Newsletter, Brunel University, May 2010]

Freakonomics, Bananomics and Lovenomics

Economics is good fun. Not always, for sure, but often it really is. Those of us who have chosen to pursue an academic career in this discipline of course know it – and so we frequently fall into passionate discussions whether a particular relationship might be endogenous, we marvel at the elegance of a new theoretical proof, and we travel to conferences to boast about our new and exciting research to our colleagues and peers. Yet, the rest of mankind often fails to appreciate the beauty of economic and considers it rather boring (and I suspect that even some of our students may feel that way!). But every now and then, an economist comes up with a new article or book that makes even the non-economists smile and think.

Freakonomics was just such a book. Published in 2005 by a University of Chicago economist Steven Levitt, it succeeded in convincing the popular public that economics can be fun and also that it can shed light on important real-world questions at the same time. The book encompasses a broad range of topics, from analyzing results of school tests or sport events to identify cheating, through arguing that abortions helped lower crime in the US, to analyzing the economics of drug dealing. The book quickly became a best seller – and soon a sequel, blog and movie followed on the coat tails of its success.

Of course, Steve Levitt is not the only academic economist capable of producing research that is publishable and fun to read at the same time. As the title of this short contribution suggests, I want to talk about two other examples. And only one of them is shameless self-promotion.

I am writing this on my way from an international conference where I have seen a presentation by Richard Jong-A-Pin from the University of Zurich entitled “Are Banana Republics Banana Republics?”. The term banana republic is used to denote countries marked by high degree of political instability and dysfunctional state institutions (Woody Allen’s movie “Bananas” depicts the stereotypical image of a banana republic rather well). So Richard in his paper asks a simple and intuitive question: do countries producing bananas really suffer from higher political instability? This question, however, is more complicated than the first look suggests, because there is a possibility of reverse causality: what if politically unstable countries are more likely to produce bananas? Richard resolves the question of endogeneity by means of instrumental variables – he uses a set of third variables, unrelated to political instability, to predict whether a particular country produces bananas and then uses the predicted banana production rather than the actual one to explain political instability. This approach ensures that the regression analysis only picks up causality going from bananas to political instability and not the other way around. Doing so, he finds that banana republics indeed have higher political instability than countries that do not produce bananas.

Now this result begs the follow-up question why banana republics are banana republics. In other words, why are bananas apparently detrimental to political developments? Richard's paper does not address this question but a plausible explanation was suggested by Ronald Wintrobe (University of Western Ontario) who commented on Richard’s paper at the same conference. Bananas, as some other agricultural crops, perish quickly and this creates fertile ground for rent seeking. Let me explain. Suppose I want to buy a truck load of bananas and find a farmer – in an anonymous banana republic – who is happy to sell his bananas to me. We agree the terms of the deal months in advance – but when the bananas are ready to be delivered, I renege on our original agreement and insist on a substantial discount. The farmer now has few options other than accept my ultimatum: he will have a hard time finding a different buyer at such a short notice while taking me to court would take months – and his bananas would rot in the meantime. My bargaining position is therefore much stronger than his and in the end I can get almost any discount I want. The eventual outcome of this, however, may be that banana-producing countries develop a culture of rent seeking – and this eventually translates into political life too. Hence, producing bananas indeed breeds political instability. Watches, on the other hand, are not perishable and therefore Switzerland is not a banana republic.

And now for something completely different. Studying the formation (and dissolution) of relationships has a long tradition in economics, especially since the publication of Gary Becker's seminal “Theory of Marriage” in the Journal of Political Economy in1973. In my recent paper entitled “Anthropometry of Love,” written jointly with Michèle Belot from Oxford, we analyze a peculiar – and at a first sight puzzling – feature of interethnic marriages: men and women belonging to the same ethnic minority group are not always equally likely to intermarry with whites. Among blacks, it is black men who intermarry much more often than black women. The reverse holds for East Asians (for example the Chinese): in this case, women are much more likely to have a white partner than men. These asymmetries could be due to a number of factors. For example, it may be that black men and East Asian women are more numerous in the British society due to the supply of immigrants and/or due to past immigration policies. But that does not appear to be the case, as a quick look at the summary census figures confirms. Another possibility is that men or women of a particular ethnic group are more likely to possess characteristics that make them attractive in the marriage market, such as being more educated or richer. But again, data fail to confirm this view. Instead, we propose an explanation based on physical characteristics, in particular height. There are sizeable differences in height across the different ethnic groups in the UK: the whites and blacks are the tallest, followed by Indians, Pakistani and Chinese while Bangladeshi happen to be the shortest. This can have important implications for marriage-market participation of ethnic minorities and for interethnic marriage as across all ethnicities, we can observe a strong preference for the husband to be taller than his wife. This implies that men and women from the same ethnic group face different distributions of potential marriage partners in the white segment of the marriage market. Specifically, relatively tall men and short women have a wider choice of white partners than short men and tall women. Hence, black men, being relatively tall, are ‘on the top of the food chain’ (to quote an unnamed Brunel student), unlike black women. And, similarly, Chinese and other East Asian women have a similarly wide choice, unlike their male counterparts. So far so good but do the data support this explanation? Using data from the Millennium Cohort Study, we estimate regressions explaining the probability that a member of an ethnic minority has a white partner. We include in our regressions controls for the share of suitable partners – defined for men as those who are shorter and for women as those who are taller than the individual in question – both within the white population and within one’s own ethnic group. Doing so improves the quality of the regression and helps reduce the unexplained variation in the patterns of intermarriage. Height, however, is not the only explanation of intermarriage patterns; cultural norms, for example, are certain to matter too. But it is one of the factors underlying the observed differences. Furthermore, the importance of height for inter-ethnic marriage has some unexpected implications. Firstly, as social attitudes towards interethnic marriage become more liberal, this increases the number of potential marriage partners for black men and East-Asian women but may reduce it for black women and East-Asian men. Secondly, immigration has a marriage-market effect which is different for men and women. And how about policy implications? I am afraid there are none: love and the marriage market are (so far) largely free from government interference. Should this change, I would suggest subsidies for couples involving East-Asian men and black women.

[Originally published in Economics and Finance Newsletter, Brunel University, April 2010]