Are stock markets efficient in the sense that stock prices reflect all available information? This question has preoccupied finance lately as many have started to doubt the efficient market hypothesis during the latest crisis. One critical aspect of this is whether current tests of the hypothesis actually give an accurate picture, and if not whether this matters in a significant way.
Tarek Hassan and Thomas Mertens
claim that it is possible for stock markets to aggregate information properly, that small errors at the household level can accumulate and amplify if these errors are correlated, and that the welfare consequences can be substantial even if the initial errors were small. This cost emerges for a portfolio misallocation due to the higher volatility of stock prices. To get to such a result, they take a standard real business cycle model, add to it that households get a noisy private signal about future total factor productivity. They then look at the stock market for additional information to form expectations. If you allow households to be on average more optimistic than rationality in some state, and more pessimistic in others, you get the above results. Interestingly, Hassan and Mertens show that households face little incentives to correct individually for these small common errors (0.01% of average consumption), but collectively the consequences are large (2.4%). Talk about an amplification.
Thursday, June 9, 2011
Wednesday, June 8, 2011
Pollution has an impact on worker productivity
Pollution regulation is typically cast as a game between citizens and firms, the first suffering the consequences of pollution while the second are the origin of the pollution. In such a case, there is no incentive for firms to abate pollution, and the government has to mediate. But could a case be made that firms should be willing, individually or collectively, to reduce pollution. One way can be green labeling, which could increase the demand for their products. Another would be if firms realize pollution has an impact on their on productivity or on the labor supply.
Joshua Graff Zivin and Matthew Neidell take the worker productivity angle by using a dataset of dairy farm workers from a large farm in the Central Valley of California. In particular, they look how ozone levels impact the output of piece rate workers. At it is substantial. For example, a 10 ppb reduction of ozone increases productivity by 4.2%, noting that the standard deviation of ozone levels is 13 ppb. And if you object that some of the workers fall under minimum wage law and may not exert the right effort, be reassured, the authors took that into account. In addition, this impact happens even when the ozone level is well below the current national standards. Realizing this, industry should be more willing to accept the suggested tightening of pollution standards for ozone, and for nitrogen oxides and volatile organic chemicals that are the source of ground-level ozone.
Joshua Graff Zivin and Matthew Neidell take the worker productivity angle by using a dataset of dairy farm workers from a large farm in the Central Valley of California. In particular, they look how ozone levels impact the output of piece rate workers. At it is substantial. For example, a 10 ppb reduction of ozone increases productivity by 4.2%, noting that the standard deviation of ozone levels is 13 ppb. And if you object that some of the workers fall under minimum wage law and may not exert the right effort, be reassured, the authors took that into account. In addition, this impact happens even when the ozone level is well below the current national standards. Realizing this, industry should be more willing to accept the suggested tightening of pollution standards for ozone, and for nitrogen oxides and volatile organic chemicals that are the source of ground-level ozone.
Tuesday, June 7, 2011
Does it make sense to subsidize biofuels?
Ina relatively short time, biofuels have become remarkably popular, especially as an additive to regular petroleum based fuel. This is at least in part due to massive subsidies from the US to fuel and corn producers. As biofuels compete with food, this has lead to major price increases for corn and sugar, with adverse consequences for importing countries. This begs the question: is it actually a good idea to subsidize biofuels? I mentioned previously that it is preferable to tax other energy products rather than subsidize alternative energies (1, 2), but let us revisit this issue.
Subhayu Bandyopadhyay, Sumon Bhaumik and Howard Wall use a general equilibrium trade model and confirm that if there is a Pigovian tax on conventional fuels, subsidies are not needed. But if the Pigovian tax is not available or too low (as is the case in the US), then a subsidy for biofuels makes sense, But if the country in question is large, there are other implications through increased worldwide demand for food. In that case, a food exporter wants to subsidize biofuels and tax conventional fuels. A food importing country would only want to subsidize biofuels if the pollution reduction effect is large enough.
Hector Nuñez, Hayri Önal, Madhu Khanna, Xiaoguang Chen and Haixiao Huang look more specifically at the interaction of policies in the US and Brazil, the two largest producers of biofuels. Indeed, the US imposes a special tariff on the importation of biofuels, in particular the more advanced sugarcane based one from Brazil. Brazil is also the largest producer and exporter of beef. The paper uses a multi-country, multi-good model, unfortunately with a partial equilibrium, but it takes into account possible crop rotations and different categories of land. It concludes that eliminating the tariffs would significantly reduce biofuel production in the US, with the latter importing biofuels from Brazil and exporting corn. While this reduces producer welfare compared to the status quo, it increases consumer welfare. Given the political system in the US, guess what will happen.
Subhayu Bandyopadhyay, Sumon Bhaumik and Howard Wall use a general equilibrium trade model and confirm that if there is a Pigovian tax on conventional fuels, subsidies are not needed. But if the Pigovian tax is not available or too low (as is the case in the US), then a subsidy for biofuels makes sense, But if the country in question is large, there are other implications through increased worldwide demand for food. In that case, a food exporter wants to subsidize biofuels and tax conventional fuels. A food importing country would only want to subsidize biofuels if the pollution reduction effect is large enough.
Hector Nuñez, Hayri Önal, Madhu Khanna, Xiaoguang Chen and Haixiao Huang look more specifically at the interaction of policies in the US and Brazil, the two largest producers of biofuels. Indeed, the US imposes a special tariff on the importation of biofuels, in particular the more advanced sugarcane based one from Brazil. Brazil is also the largest producer and exporter of beef. The paper uses a multi-country, multi-good model, unfortunately with a partial equilibrium, but it takes into account possible crop rotations and different categories of land. It concludes that eliminating the tariffs would significantly reduce biofuel production in the US, with the latter importing biofuels from Brazil and exporting corn. While this reduces producer welfare compared to the status quo, it increases consumer welfare. Given the political system in the US, guess what will happen.
Monday, June 6, 2011
Shortsightedness and tariffs
International trade theory is in large part about optimal trade theory, yet it is incapable to explain the observed level of tariffs. While under rather general circumstances theory will tell you that zero tariffs will improve general welfare, once you take into account that governments threaten and negotiate in a Nash equilibrium, tariffs should be at about 30%. They are generally far below that. It is a big challenge to explain the difference.
Mario Larch and Wolfgang Lechthaler argue that all that is needed is for trade theory to finally catch up with the rest of economics and use some dynamics. Specifically, transform the problem into a dynamic Nash equilibrium, take into account transition paths, and you get some realistic numbers if you assume that the negotiating politicians are short-sighted, which is certainly not far from the truth. This is important because the various transitional effect of a tariff change take different times. Indeed a decrease in tariffs has a faster and positive impact on consumption through an immediate increase in consumption. A counter-effect through the closing of inefficient firms takes much longer. Impatient politicians discount heavily the latter.
Mario Larch and Wolfgang Lechthaler argue that all that is needed is for trade theory to finally catch up with the rest of economics and use some dynamics. Specifically, transform the problem into a dynamic Nash equilibrium, take into account transition paths, and you get some realistic numbers if you assume that the negotiating politicians are short-sighted, which is certainly not far from the truth. This is important because the various transitional effect of a tariff change take different times. Indeed a decrease in tariffs has a faster and positive impact on consumption through an immediate increase in consumption. A counter-effect through the closing of inefficient firms takes much longer. Impatient politicians discount heavily the latter.
Friday, June 3, 2011
Should voting be compulsory?
Should one force people to vote? While there are clear incentives for people not to vote because it is very unlikely their individual vote would matter, there may be a social benefit to make sure that everyone, or at least many people, votes. Clearly, public decision-making is difficult when people do not voice an opinion. But imagine you are forced to vote, how should you vote? Selfishly, or for the public good? And how should that public good be defined? Your family, the neighborhood, your clan, your country? Indeed, if you force someone to vote, you must have an idea for what purpose you impose this.
Dan Usher tries to make sense of all this focusing on the idea of the duty to vote, the duty being an unenforceable obligation. The paper is impossible to summarize without making a massacre of it, so I will abstain. It is full of ideas on how to think about the duty to vote, abstention, and mandatory voting. Read it if you are interested.
Dan Usher tries to make sense of all this focusing on the idea of the duty to vote, the duty being an unenforceable obligation. The paper is impossible to summarize without making a massacre of it, so I will abstain. It is full of ideas on how to think about the duty to vote, abstention, and mandatory voting. Read it if you are interested.
Thursday, June 2, 2011
Seat belts lead to safer driving
A classic example of the law of unintended consequences is how seat belt laws gave reasons to drive more dangerously, as car drivers feel more secure. This idea has been popularized by Sam Peltzman and several follow-up studies.
Yong-Kyun Bae puts some serious doubts in this results by pointing out that all these studies were based on aggregate data. Using individual data, which allows to exploit individual characteristics, as well as the circumstances of accidents. And once you control for these factors and exploit cross-state variations of how seat-belt laws became more or less stringent in the last decade, it appears more stringent laws make people drive more carefully. Indeed, pedestrians are getting safer. If this result stands, the challenge is to explain it: do tougher seat-belt laws signal stronger enforcement of other traffic laws? In particular, as Bae suggests, these laws may come in tandem with cell-phone and texting-while-driving laws.
Yong-Kyun Bae puts some serious doubts in this results by pointing out that all these studies were based on aggregate data. Using individual data, which allows to exploit individual characteristics, as well as the circumstances of accidents. And once you control for these factors and exploit cross-state variations of how seat-belt laws became more or less stringent in the last decade, it appears more stringent laws make people drive more carefully. Indeed, pedestrians are getting safer. If this result stands, the challenge is to explain it: do tougher seat-belt laws signal stronger enforcement of other traffic laws? In particular, as Bae suggests, these laws may come in tandem with cell-phone and texting-while-driving laws.
Wednesday, June 1, 2011
Risk-free rate tax deductions
The Norwegian shareholder tax is rather peculiar in that it allows the deduction of risk-free interest income, thus only taxing the risky portion of capital income. This is rather counter-intuitive, as one usually wants to encourage risk-taking in the form of venture capital or plain entrepreneurship. But the idea in Norway was that this would make financing of firms neutral with respect to the source of funds.
Jan Södersten and Tobias Lindhe argue this line of reasoning is not appropriate for an open economy like Norway and 56% foreign ownership. Indeed, one needs to understand as well who is investing. Indeed, taxes are capitalized differently by different people. Indeed, for an economy that is so open, returns are largely determined on international markets, What is then determinant for Norway is the after-tax return, and this is where new distortion enter the picture: large firms are financed on international markets, and the after-tax rate is set abroad. Small firms that finance themselves domestically have provide similar after-tax returns, but domestic investors face different tax rules than their foreign counterparts. This is where new distortions can enter, and severe under-investment in domestic firms could be the consequence. But for a rather closed economy, this seems a good idea, especially as it is a neat way to prevent under-reporting of income.
Jan Södersten and Tobias Lindhe argue this line of reasoning is not appropriate for an open economy like Norway and 56% foreign ownership. Indeed, one needs to understand as well who is investing. Indeed, taxes are capitalized differently by different people. Indeed, for an economy that is so open, returns are largely determined on international markets, What is then determinant for Norway is the after-tax return, and this is where new distortion enter the picture: large firms are financed on international markets, and the after-tax rate is set abroad. Small firms that finance themselves domestically have provide similar after-tax returns, but domestic investors face different tax rules than their foreign counterparts. This is where new distortions can enter, and severe under-investment in domestic firms could be the consequence. But for a rather closed economy, this seems a good idea, especially as it is a neat way to prevent under-reporting of income.
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