Tag Archives: incentives

Committing to an experimental design without revealing it

Pre-registering an experiment in a public registry of clinical trials keeps the experimenters honest (avoids ex post modifications of hypotheses to fit the data and “cherry-picking” the data by removing “outliers”), but unfortunately reveals information to competing research groups. This is an especially relevant concern in commercial R&D.

The same verifiability of honesty could be achieved without revealing scientific details by initially publicly distributing an encrypted description of the experiment, and after finishing the research, publishing the encryption key. Ex post, everyone can check that the specified experimental design was followed and all variables reported (no p-hacking). Ex ante, competitors do not know the trial details, so cannot copy it or infer the research direction.

Avoiding the Bulow and Rogoff 1988 result on the impossibility of borrowing

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Bulow and Rogoff 1988 NBER working paper 2623 proves that countries cannot borrow, due to their inability to credibly commit to repay, if after default they can still buy insurance. The punishment of defaulting on debt is being excluded from future borrowing. This punishment is not severe enough to motivate a country to repay, by the following argument. A country has two reasons to borrow: it is less patient than the lenders (values current consumption or investment opportunities relatively more) and it is risk-averse (either because the utility of consumption is concave, or because good investment opportunities appear randomly). Debt can be used to smooth consumption or take advantage of temporary opportunities for high-return investment: borrow when consumption would otherwise be low, pay back when relatively wealthy.

After the impatient country has run up its debt to the maximum level the creditors are willing to tolerate, the impatience motive to borrow disappears, because the lenders do not allow more consumption to be transferred from the future to the present. Only the insurance motive to borrow remains. The punishment for default is the inability to insure via debt, because in a low-consumption or valuable-investment state of affairs, no more can be borrowed. Bulow and Rogoff assume that the country can still save or buy insurance by paying in advance, so “one-sided” risk-sharing (pay back when relatively wealthy, or when investment opportunities are unavailable) is possible. This seemingly one-sided risk-sharing becomes standard two-sided risk-sharing upon default, because the country can essentially “borrow” from itself the amount that it would have spent repaying debt. This amount can be used to consume or invest in the state of the world where these activities are attractive, or to buy insurance if consumption and investment are currently unattractive. Thus full risk-sharing is achieved.

More generally, if the country can avoid the punishment that creditors impose upon default (evade trade sanctions by smuggling, use alternate lenders if current creditors exclude it), then the country has no incentive to repay, in which case lenders have no incentive to lend.

The creditors know that once the country has run up debt to the maximum level they allow, it will default. Thus rational lenders set the maximum debt to zero. In other words, borrowing is impossible.

A way around the no-borrowing theorem of Bulow and Rogoff is to change one or more assumptions. In an infinite horizon game, Hellwig and Lorenzoni allow the country to run a Ponzi scheme on the creditors, thus effectively “borrow from time period infinity”, which permits a positive level of debt. Sometimes even an infinite level of debt.

Another assumption that could realistically be removed is that the country can buy insurance after defaulting. Restricting insurance need not be due to an explicit legal ban. The insurers are paid in advance, thus do not exclude the country out of fear of default. Instead, the country’s debt contract could allow creditors to seize the country’s financial assets abroad, specifically in creditor countries, and these assets could be defined to include insurance premiums already paid, or the payments from insurers to the country. The creditors have no effective recourse against the sovereign debtor, but they may be able to enforce claims against insurance firms outside the defaulting country.

Seizing premiums to or payments from insurers would result in negative profits to insurers or restrict the defaulter to one-sided risk-sharing, without the abovementioned possibility of making it two-sided. Seizing premiums makes insurers unwilling to insure, and seizing payments from insurers removes the country’s incentive to purchase insurance. Either way, the country’s benefit from risk-sharing after default is eliminated. This punishment would motivate loan repayment, in turn motivating lending.

Putting your money where your mouth is in policy debates

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Climate change deniers should put their money where their mouth is by buying property in low-lying coastal areas or investing in drought-prone farmland. Symmetrically, those who believe the Earth is warming as a result of pollution should short sell climate-vulnerable assets. Then everyone eventually receives the financial consequences of their decisions and claimed beliefs. The sincere would be happy to bet on their beliefs, anticipating positive profit. Of course, the beliefs have to be somewhat dogmatic or the individuals in question risk-loving, otherwise the no-agreeing-to-disagree theorem would preclude speculative trade (opposite bets on a common event).

Governments tend to compensate people for widespread damage from natural disasters, because distributing aid is politically popular and there is strong lobbying for this free insurance. This insulates climate change deniers against the downside risk of buying flood- or wildfire-prone property. To prevent the cost of the damages from being passed to the taxpayers, the deniers should be required to buy insurance against disaster risk, or to sign contracts with (representatives of) the rest of society agreeing to transfer to others the amount of any government compensation they receive after flood, drought or wildfire. Similarly, those who short sell assets that lose value under a warming climate (or buy property that appreciates, like Arctic ports, under-ice mining and drilling rights) should not be compensated for the lost profit if the warming does not take place.

In general, forcing people to put their money where their mouth is would avoid wasting time on long useless debates (e.g. do high taxes reduce economic growth, does a high minimum wage raise unemployment, do tough punishments deter crime). Approximately rational people would doubt the sincerity of anyone who is not willing to bet on her or his beliefs, so one’s credibility would be tied to one’s skin in the game: a stake in the claim signals sincerity. Currently, it costs pundits almost nothing to make various claims in the media – past wrong statements are quickly forgotten, not impacting the reputation for accuracy much.

The bets on beliefs need to be legally enforceable, so have to be made on objectively measurable events, such as the value of a publicly traded asset. By contrast, it is difficult to verify whether government funding for the arts benefits culture, or whether free public education is good for civil society, therefore bets on such claims would lead to legal battles. The lack of enforceability would reduce the penalty for making false statements, thus would not deter lying or shorten debates much.

An additional benefit from betting on (claimed) beliefs is to provide insurance to those harmed by the actions driven by these beliefs. For example, climate change deniers claim small harm from air pollution. Their purchases of property that will be damaged by a warming world allows climate change believers to short sell such assets. If the Earth then warms, then the deniers lose money and the believers gain at their expense. This at least partially compensates the believers for the damage caused by the actions of the deniers.

Volunteer parking wardens may benefit the environment

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Reducing the utility from car use and ownership motivates substitution towards other forms of transportation, which benefits both the environment and public health. One way to cut the convenience of driving is enforcing parking regulations, because drivers have to park further from their destination when the option of illegal parking becomes less attractive. Parking at a greater distance also makes people walk more – a minor health benefit.

Enforcing speed limits and other traffic rules that slow cars down increases the time cost of driving. This may reduce wear and tear on vehicles and roads, which benefits the environment.

An implication of is that people who want to reduce global warming or improve public health should become volunteer parking wardens and traffic police by reporting parking violations, speeding and dangerous driving (preferably with photo or video evidence from phones or dashboard cameras).

A possible countervailing effect of the enforcement of parking rules occurs if the illegally parked cars obstruct the movement of other cars enough to motivate some people to switch away from driving. Then stopping the parking violations may open the road up enough to encourage more use of cars, with an overall negative environmental and health effect. Similarly, if reckless drivers make the roads unsafe enough to reduce others’ car use, then making traffic civil again may attract risk-averse people back to driving. However, in most developed countries, illegal parking and the ignoring of rules of the road is not severe enough to deter driving significantly, so better enforcement is likely to reduce car use.

Slowing traffic down may increase congestion and emissions per kilometre travelled if there is little substitution away from driving. Again, in developed countries public transit and cycling are usually feasible options. Of course, some people always find excuses not to use these, and in remote rural areas public transit may indeed be economically unreasonable and distances may really be too great for bikes. Electric bikes are then an option. These increase the range of travel with less pollution and congestion than cars.

Platform providers fake being popular

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Crowdfunding platforms, stock exchanges and other providers of two-sided markets want to appear popular, because having more buyers attracts more sellers and vice versa. The platform’s revenue is usually proportional to the number of users, because it charges a commission fee on trades or advertisers pay it to show ads to users. The exchange’s marginal cost of a user is close to zero, giving it an incentive to fake a high volume of trades, a large limit order book and a small bid-ask spread.

The platform’s cost of posting a great volume of outstanding buy and sell orders at a small spread is that many investors try to trade at these favourable bid and ask prices. Either the market maker has to take the other side of these attempted transactions or is found fraudulent. Taking the other side results in a large loss if some investors are better informed than the exchange.

The platform could falsely display a large trading volume, but keep the order book honestly small by adding fake trades at prices between the bid and the ask only, so no investor’s real limit order is ignored. This seems difficult to detect, unless one side of the limit order book is empty (e.g. no buyers) and at least one at-market order on the other side (e.g. a sell) is outstanding. In this case, any trades occurring would have to satisfy the at-market order. However, the platform or real investors can then take the other side of the at-market order at a very favourable price to themselves, which discourages at-market orders. A large trading volume with a thin order book is still slightly suspicious, because it requires that crossing buy and sell orders between the bid and ask prices arrive almost simultaneously, in order to be matched without appearing on the order book for long, and without triggering the real limit orders. Displaying the fake buys and sells on the order book risks attracting actual matching trades, which the platform would have to honour (at a cost).

Without automated quote matching, there are no at-market orders, for example on the Funderbeam crowdfunding platform. Instead, everyone either posts a limit order or picks an order from the other side to trade with, e.g. a buyer chooses a sell. Investors can pick an order with a worse price (higher sell or lower buy) on the other side, which frequently occurs on Funderbeam. Choosing a worse price is irrational, unless the traders in question are colluding, so the asset is effectively not changing ownership. Reasons to carry out such seemingly irrational trades are to manipulate price and volume, e.g. price can be raised or reduced by targeted trades outside the bid-ask interval. Volume can only increase after added trades, rational or not, but such seemingly greater activity is exactly what benefits the stakeholders of the platform. The employees of the market maker have a natural motive to fake-trade between themselves to make their firm look good, even without any inappropriate pressure from their boss.

Another way to attract issuers and investors is to demonstrate successful initial public offerings, meaning that the funds are raised quickly (good for issuers) and the price of the newly listed stock (or other asset) goes up, which benefits investors. Adding fake capital-raisers is difficult, because potential investors will check the background of the supposed issuer. Inserting spoof investors into an actual funding campaign is costly, because real money would have to be invested. One way to manipulate popularity upward is to simultaneously add a fake issuer and fake investors who satisfy its funding need. The idea is to not leave time for real investors to participate in the campaign, by pretending that the capital-raiser achieved its target funding level before most investors could react. This is easier in markets with a small number of real investors and without an auto-invest feature. However, the real investors who were supposedly pre-empted may still research the supposedly very popular issuer.

A costless way to briefly boost the popularity of a real fundraising campaign is to add fake investors after the target funding is achieved, and forbid issuers from increasing the target or accepting funds from those who subscribed after the goal was reached. Any campaign meeting its target can then be made to look heavily oversubscribed. However, if the issuers are informed in advance of the restriction not to increase the target, then they may find an alternative unrestricted platform to raise funds. On the other hand, if the restriction is not mentioned beforehand, then it will likely anger the issuers who will then create negative publicity for the platform. Competition between exchanges thus curtails their manipulation incentives.

The platform can motivate real investors to raise their bids when the campaign reaches its target by rationing demand: bidders in an oversubscribed share issue get only a fraction of what they wanted to buy. Anticipating this, buyers will increase their requested quantities so that the fraction of their new bid equals their actual demand. This makes the campaign look oversubscribed and creates a feedback loop: if other investors increase their quantities, then rationing reduces the fraction of a given investor’s demand that will be satisfied, so this investor raises her or his requested amount, which in turn makes others increase theirs.

If investors know of the bid rationing in advance, then they may select a rival market provider without this restriction, but if rationing takes them by surprise, then they may leave and publicly criticise the platform. Capital-raisers compare exchanges, so if many market providers inflate demand and the issuers pay attention to the level of oversubscription (instead of the fraction of campaigns reaching the target, which is what should matter to the capital-raiser), then the biggest inflator wins. Of course, platforms may not want to reveal unsuccessful campaigns (e.g. Funderbeam does not), so public data on the fraction of issuers who achieved their funding goal is unlikely to exist.

Theoretically, the feedback from bid rationing to increased quantity demanded could lead to infinite amounts requested. A countervailing incentive is that with positive probability, other investors do not honour their commitment to buy, in which case a given investor may be required to buy the amount (s)he demanded, instead of the lower amount (s)he actually wanted. If there is no commitment to buy (for example, on Funderbeam the bids are only non-binding indications of interest), then the danger of overcommitting is absent, so the rational choice seems to be requesting an infinite amount. Investors do not indicate infinite interest, so either they are irrational or some other penalty exists for outbidding one’s capability to pay.

Star job candidates benefit from appearing to be worse

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Employers have a cost of making a job offer: filling out forms, getting approval, not being able to make other offers simultaneously in case too many job candidates accept, etc. A company who believes that it is not the top choice of candidates would want to avoid making an offer to a star applicant (one who is likely to receive better alternative offers from top employers, thus turn down the lower-ranked company’s offer).

If the star job-seeker is uncertain about the offers she or he will get, or wants a bargaining chip to use with the most preferred company, then (s)he prefers to obtain the lower-ranked employer’s offer, even when planning to reject it. A way to entice the company into offering a job is to pretend to be more attainable (have a worse outside option) by faking lower talent and potential when interviewing with lower-ranked employers. For this pretence to be (partly) credible, it must have a cost for the job-seeker, otherwise all the best candidates would pretend to be worse and increase their chance of obtaining offers from their backup employers. Then the next-best candidates would have to fake being less good to receive jobs, etc. This race to the bottom would only end once all candidates look like the worst possible, which does not seem realistic.

One potential cost is that faking lower talent has a random outcome, which may be so bad that the employer does not want to offer a job at all. This would temper the incentive to appear worse. Another cost is information leakage – if bad performance at a less desirable interview becomes known to higher-ranked employers, then the candidate may forfeit her or his most preferred interviews and jobs. It could also be that the top job-seekers cannot hide their quality, for example because their genius shines out despite their best effort, or employers base offers solely on recommendation letters, which the candidate cannot see or affect around the time of applying.

Equilibrium response to reduced material use for plastic bags

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Probably to save material on the manufacture of the free plastic shopping bags in the US, these bags are small and thin compared to the ones in Estonia (which used to be free, but are now priced at significantly above production cost due to EU regulations on disposable plastic products). The equilibrium response of cashiers and customers to thin flimsy bags is to double-bag groceries, a practice unheard of in Estonia. After all, if one bag is sturdy enough, almost nobody will use two inside each other. I have successfully carried 10 kg in an Estonian plastic bag.

The equilibrium response to small bags is to distribute the groceries among many bags, especially the heavy or bulky items, for example to put each milk canister or large salad sack into a separate bag. Both double-bagging and the one-item-per-bag distribution lead to more bags being used in response to manufacturing each bag out of less material. It is an empirical question whether thinner, smaller bags result in less or more plastic waste overall. To incentivise reducing the one-time use of plastic bags and to encourage reuse, customers should have to pay for these, like in the EU.

One form of plastic bag reuse is as garbage bags (although it is only a one-time reuse, it is better than nothing). However, the flimsy free bags in the US come in bulk packs with the bottoms of the bags stuck together, so separating one from the stack often results in holes in its bottom an inch wide or more. The holes discourage many forms of reuse, including as trash bags, because small items (dust, crumbs, scraps) fall out. Partly the holes are due to the flimsiness of the material, partly to the way the bags are glued together to make a bulk pack.

Fund management fee paid explicitly to nudge consumers to choose better funds

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Mutual funds with lower management fees have higher future before-fee returns (Gil-Bazo and Ruiz-Verdu 2009). Nonetheless, the high-fee funds have not gone out of business, so there must exist a sizable number of silly customers who accept low returns without switching to competitors. When asked explicitly, all fund investors prefer more money to less. Their hourly wage is not large enough to explain their non-switching with the time and hassle costs of comparing fund returns and choosing a new one. Similarly, many Estonians keep their retirement savings in badly performing high-fee pension funds despite the availability of dominating options (Tuleva and LHV index tracking funds). This is costing the customers over one percent of their retirement wealth per year.

By contrast, people with chronic or expensive diseases in the US often pick the health insurance plan that maximises their wealth (coverage minus premiums). This dynamic optimisation involves switching to a different plan when their illness changes. People without costly medical conditions tend not to switch their insurance even when cheaper plans with higher coverage are available.

Both the pension and the insurance plan decisions are complex, but matter greatly for wealth. Why do people pay attention to the financial consequences of their insurance choice when sick, but ignore better options among pension funds (and when healthy, also among insurance plans)? One possibility is that insurance is more salient to the sick, and the greater attention leads to better decisions. Specifically, the premiums and out of pocket payments for medical procedures frequently remind patients of the financial consequences of their insurance, but the missing returns on one’s retirement assets are not observed without explicit comparison to the stock market or competing funds. Most people do not compare their pension plan to the market, so even in retirement may not know what their (counterfactual) wealth would have been had they chosen a better fund .

If it is lack of attention that causes the bad choice of mutual and pension funds, then one solution (proposed by my friend Hongyu Zhang) is to make the management fees more salient by requiring their explicit payment. For example, every month the customer has to transfer the amount of the management fee from their bank account to the fund. Financially, this is equivalent to the fee being deducted from the retirement assets like now (assuming these assets are eventually taxed the same as income, otherwise the transferred fee can be adjusted to make it financially equivalent to the deduction). The attention required is however greater for an explicit payment than for doing nothing following a lack of capital gains. Similarly, requiring customers to pay the difference between the return of their fund and the market return into the fund every two weeks would nudge them towards greater attention to their retirement account.

In practice, such a nudge is unfortunately politically infeasible. Not only would the fund industry lobby against it, but voters would irrationally perceive the required explicit payments as increased taxes. This would make the transition to transferring fees to funds from customers’ bank accounts very unpopular. If people understood the equivalence between low returns on their assets and explicit payments required of them, then they would be financially literate enough to choose low-fee, high-return index funds in the first place. Thus the problem of low-performing pension funds would be absent. To sum up, the fool and his money are soon separated, and it is difficult to protect people from their own bad decisions.

Why research with more authors gets cited more

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Empirically, articles with more authors are cited more, according to Wuchty et al. (2007). The reasons may be good or bad. A good reason is that coauthored papers may have higher quality, e.g. due to division of labour increasing the efficiency of knowledge production. I propose the following bad reasons, independent of potential quality differences between coauthored and solo articles. Suppose that researchers cite the works of their friends more frequently than warranted. A given scientist is more likely to have a friend among the authors of an article with a greater number of collaborators, which increases its probability of getting a „friendly citation”.

Another reason is defensive citing, i.e. including relatively unrelated papers in the reference list before submitting to a journal, in case the referees happen to be the authors of those works. The reason for adding these unnecessary citations is the belief, warranted or not, that a referee is more likely to recommend acceptance of a paper if it cites the referee’s publications. The probability that the set of referees overlaps with the set of authors of a given prior work increases in the number of authors of that work. Thus defensive citing is more effective when targeted to collaborative instead of solo papers.

The referees may also directly ask the author to cite certain papers in the revision (I have had this experience). If the referees are more likely to request citations to their own or their coauthors’ work, then articles with more authors are again referenced more.

Valderas et al. (2007) offer some additional explanations. One is measurement error. Suppose that letters to the editor, annual reports of the learned society, its presidential inaugural addresses, and other non-research in scientific journals are counted as publications. These have both fewer authors and citations than regular research articles, which creates a positive correlation between the popularity of a piece of writing and its number of authors.

If self-citations are not excluded and researchers cite their own work more frequently than that of others, then papers with more authors get cited more.

Articles with more collaborators are presented more frequently, thus their existence is more widely known. Awareness of a work is a prerequisite of citing it, so the wider circulation of multi-author publications gives them a greater likelihood of being referenced, independent of quality.

Pill testing, placebos and illegal market efficiency

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Testing illegal drugs for the active ingredient differs from testing for poisonous adulterants. Both tests have opposite effects on drug use before and after buying. After the pill has been purchased, testing reduces use, because sometimes the drug fails the test, whether correctly or not, and is discarded. Before purchase, the option to test for and avoid adulterated or inactive drugs reduces the buyer’s risk, thus increases use.

In the longer term, testing benefits the dealers of purer, more predictable and less toxic drugs, putting some suppliers of fakes out of business. Pill predictability reduces overdoses – a health effect similar to lower toxicity. If old drugs can be tested, but new ones not, then buyers experiment less and the incentive to invent new narcotics decreases.

The avoidance of poisonous adulterants is good for public health, but purer pills not necessarily so. Inactive drugs undermine consumer confidence in the illegal market, reducing use, prices and casual purchases. Trust then requires a long-running relationship with the seller, which has multiple benefits. It motivates dealers to care about the health of their loyal customers, simplifies policing and gives researchers and social workers better long-term access to the at-risk population.

One claimed benefit of party drugs is that they reduce anxiety, increase the user’s confidence and social interaction, thus improving mental health. Evidence from psychiatric medicines suggests that many such benefits are due to the placebo effect. Users are quite inaccurate in estimating the purity of ingested drugs, and factors like price and place of purchase strongly influence their perception of purity. The price per pure gram is negatively related to purity in some markets, further supporting the placebo interpretation. If inactive pills boost confidence similarly to illegal drugs, then there is a clear case for flooding the market with harmless placebos. The availability of pill tests for the active ingredient reduces this opportunity to make the illegal market inefficient. Tests for toxic adulterants, however, actually favour harmless placebos.