Author Archives: sanhei

Identifying useful work in large organisations by revealed preference

Some members of large organisations seemingly do work, but actually contribute negatively by wasting other people’s time. For example, by sending mass emails, adding regulations, changing things for the sake of changing them (and to pad their CV with „completed projects”) or blocking change with endless committees, consultations and discussions with stakeholders. Even if there is a small benefit from this pretend-work, it is outweighed by the cost to the organisation from the wasted hours of other members. It is difficult to distinguish such negative-value-added activity from positive contributions (being proactive and entrepreneurial, leading by example). Opinions differ on what initiatives are good or bad and how much communication or discussion is enough.
Asking others to rate the work of a person would be informative if the feedback was honest, but usually people do not want to officially criticise colleagues and are not motivated to respond thoughtfully to surveys. Selection bias is also a problem, as online ratings show – the people motivated enough to rate a product, service or person are more likely to have extreme opinions.
Modern technology offers a way to study the revealed preferences of all members of the organisation without taking any of their time. If most email recipients block a given sender, move her or his emails to junk or spend very little time reading (keeping the email open), then this suggests the emails are not particularly useful. Aggregate email activity can be tracked without violating privacy if no human sees information about any particular individual’s email filtering or junking, only about the total number of people ignoring a given sender.
Making meetings, consultations and discussions optional and providing an excuse not to attend (e.g. two voluntary meetings at the same time) similarly allows members of the organisation „vote with their feet” about which meeting they find (more) useful. This provides an honest signal, unlike politeness-constrained and time-consuming feedback.
Anonymity of surveys helps mitigate the reluctance to officially criticise colleagues, but people may not believe that anonymity will be preserved. Even with trust in the feedback mechanism, the time cost of responding may preclude serious and thoughtful answers.

The most liveable cities rankings are suspicious

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The „most liveable cities” rankings do not publish their methodology, only vague talk about a weighted index of healthcare, safety, economy, education, etc. An additional suspicious aspect is that the top-ranked cities are all large – there are no small towns. There are many more small than big cities in the world (this is known as Zipf’s law), so by chance alone, one would expect most of the top-ranked towns in any ranking that is not size-based to be small. The liveability rankings do not mention restricting attention to sizes above some cutoff. Even if a minimum size was required, one would expect most of the top-ranked cities to be close to this lower bound, just based on the size distribution.

The claimed ranking methodology includes several variables one would expect to be negatively correlated with the population of a city (safety, traffic, affordability). The only plausible positively size-associated variables are culture and entertainment, if these measure the total number of venues and events, not the per-capita number. Unless the index weights entertainment very heavily, one would expect big cities to be at a disadvantage in the liveability ranking based on the correlations, i.e. the smaller the town, the greater its probability of achieving a given liveability score and placing in the top n in the rankings. So the “best places to live” should be almost exclusively small towns. Rural areas not so much, because these usually have limited access to healthcare, education and amenities. The economy of remote regions grows less overall and the population is older, but some (mining) boom areas radically outperform cities in these dimensions. Crime is generally low, so if rural areas were included in the liveability index, then some of these would have a good change of attaining top rank.

For any large city, there exists a small town with better healthcare, safety, economy, education, younger population, more entertainment events per capita, etc (easy examples are university towns). The fact that these do not appear at the top of a liveability ranking should raise questions about its claimed methodology.

The bias in favour of bigger cities is probably coming from sample selection and hometown patriotism. If people vote mostly for their own city and the respondents of the liveability survey are either chosen from the population approximately uniformly randomly or the sample is weighted towards larger cities (online questionnaires have this bias), then most of the votes will favour big cities.

Overbidding incentives in crowdfunding

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Crowdfunding campaigns on Funderbeam and other platforms fix a price for the shares or loan notes and invite investors to submit the quantity they want to buy. If demand exceeds supply, then the financial instruments are rationed pro rata, or investors requesting quantities below a threshold get what they asked and others receive the threshold amount plus a pro rata share in the remaining quantity after the threshold amounts are allocated. Rationing creates the incentive to oversubscribe: an investor who wants n shares and expects being rationed to fraction x of her demanded quantity will rationally put in the order for n/x>n shares to counteract the rationing. For a mechanism not to invite such manipulation, the amount allocated to a given bidder in the event of oversubscription should not depend on that bidder’s bid quantity. For example, everyone gets the minimum of their demanded amount and a threshold quantity, where the threshold is determined so as to equate demand and supply. If there are s shares and all m investors demand more than s/m, then each gets s/m.

If some investors demand less than s/m, then the allocation process is recursive as follows. The i1 investors who asked for less than s/m each get what they requested. Their total t1 is subtracted from s to get s1 and the number of remaining investors reduced to m1=m-i1. Then the i2 investors asking for less than s1/m1 get what they demanded (t2 in total), and the new remaining amount s2=s1-t2 and number of investors m2=m1-i2 determined. Repeat until the number of investors asking for less than sj/mj is zero. Divide the remaining amount equally between the remaining investors.

An alternative is to let the market work by allowing the price to adjust, instead of fixing it in advance. Everyone should then submit demand curves: for each price, how many shares are they willing to buy. This may be too complicated for the unsophisticated crowdfunding investors.

However, complexity is probably not the main reason for the inefficient allocation mechanism that invites overbidding. The crowdfunding platform wants to appear popular among investors to attract companies to raise funds on it, so wants to increase the number of oversubscribed campaigns. Rationing is a way to achieve such manipulation if the fundraisers ignore the investors’ incentives to overbid and do not compare the platform to competing ones with similar allocation mechanisms. If fundraisers are irrational in this way, then they do not choose competing platforms without overbidding incentives, because funding campaigns there seem to attract less investor interest. Competing platforms with more efficient allocation mechanisms then go out of business, which eliminates comparison possibilities.

Bending polycarbonate glasses

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Polycarbonate glasses (sunglasses, safety goggles) can be bent to better fit one’s head by heating the thermoplastic polymer with a lighter, gas stove or other heat source. Example photos are below. Polycarbonate is not flammable and tolerates repeated heating and cooling. The only problem is that the paint discolours when heated and the plastic buckles and wrinkles when bent, so the lenses should not be heated, lest they become unusable. However, for the handles, a better fit outweighs cosmetic appearance in many applications.

Feedback requests by no-reply emails

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„We value your feedback” sent from a no-reply email address shows not only that the feedback is not valued, but also that the organisation is lying. More generally, when someone’s words and deeds conflict, then this is informative about his or her lack of truthfulness. If in addition the deeds are unpleasant, then this is the worst of the four possibilities (good or bad deeds combined with honest admission or lying).

The fact of sending such no-reply feedback requests suggests that either the organisations doing it are stupid, needlessly angering customers with insincere solicitations, or believe that the customers are stupid, failing to draw the statistically correct (Bayesian) conclusion about the organisation.

Some organisations send an automated feedback request by email (Mintos) or post (Yale Student Health) in response to every inquiry or interaction, even ones that clearly did not resolve the problem. The information about the non-resolution could easily be scraped from the original customer emails, without wasting anyone’s time by asking them to fill out feedback forms. The inefficient time-wasting by sending feedback requests is again informative about the organisation.

Blind testing of bicycle fitting

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Claims that getting a professional bike fit significantly improves riding comfort and speed and reduces overuse injuries seem suspicious – how can a centimetre here or there make such a large difference? A very wrong fit (e.g. an adult using a children’s bike) of course creates big problems, but most people can adjust their bike to a reasonable fit based on a few online suggestions.

To determine the actual benefit of a bike fit requires a randomised trial: have professionals determine the bike fit for a large enough sample of riders, measure and record the objective parameters of the fit (centimetres of seatpost out of the seat tube, handlebar height from the ground, pedal crank length, etc). Then randomly change the fit by a few centimetres or leave it unchanged, without the cyclist knowing, and let the rider test the bike. Record the speed, ask the rider to rate the comfort, fatigue, etc. Repeat for several random changes in fit. Statistically test whether the average speed, comfort rating and other outcome variables across the sample of riders are better with the actual fit or with small random changes. To eliminate the placebo effect, blind testing is important – the cyclists should not know whether and how the fit has been changed.

Another approach is to have each rider test a large sample of different bike fits, find the best one empirically, record its objective parameters and then have a sample of professional fitters (who should not know what empirical fit was found) choose the best fit. Test statistically whether the professionals choose the same fit as the cyclist.

A simpler trial that does not quite answer the question of interest checks the consistency of different bike fitters. The same person with the same bike in the same initial configuration goes to various fitters and asks them to choose a fit. After each fitting, the objective sizing of the bike is recorded and then the bike is returned to the initial configuration before the next fit. The test is whether all fitters choose approximately the same parameters. Inconsistency implies that most fitters cannot figure out the objectively best fit, but consistency does not imply that the consensus of the fitters is the optimal sizing. They could all be wrong the same way – consistency is insufficient to answer the question of interest.

Privacy reduces cooperation, may be countered by free speech

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Cooperation relies on reputation. For example, fraud in online markets is deterred by the threat of bad reviews, which reduce future trading with the defector. Data protection, specifically the “right to be forgotten” allows those with a bad reputation to erase their records from the market provider’s database and create new accounts with a clean slate. Bayesian participants of the market then rationally attach a bad reputation to any new account (“guilty until proven innocent”). If new entrants are penalised, then entry and competition decrease.

One way to counter this abusing of data protection laws to escape the consequences of one’s past misdeeds is to use free speech laws. Allow market participants to comment on or rate others, protecting such comments as a civil liberty. If other traders can identify a bad actor, for example using his or her government-issued ID, then any future account by the same individual can be penalised by attaching the previous bad comments from the start.

Of course, comments could be abused to destroy competitors’ reputations, so leaving a bad comment should have a cost. For example, the comments are numerical ratings and the average rating given by a person is subtracted from all ratings given by that person. Dividing by the standard deviation is helpful for making the ratings of those with extreme opinions comparable to the scores given by moderates. Normalising by the mean and standard deviation makes ratings relative, so pulling down someone’s reputation pushes up those of others.

However, if a single entity can control multiple accounts (create fake profiles or use company accounts), then he or she can exchange positive ratings between his or her own profiles and rate others badly. Without being able to distinguish new accounts from fake profiles, any rating system has to either penalise entrants or allow sock-puppet accounts to operate unchecked. Again, official ID requirements may deter multiple account creation, but privacy laws impede this deterrence. There is always the following trilemma: either some form of un-erasable web activity history is kept, or entrants are punished, or fake accounts go unpunished.

Committing to an experimental design without revealing it

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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.

Asking questions of yourself

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To make better decisions, ask about all your activities “Am I doing this right? Is there a better way?” I would have benefited from considering such questions about many everyday tasks. For example, I brushed my teeth wrong (sawing at the roots) until late teens, brushed my teeth at the wrong time (right after a meal when the enamel is soft) until my 30s. I only learned to cut my own hair in my mid-20s, and this was the highest-return investment I ever made, because a hair clipper costs as much as a haircut, so pays for itself with the first use.

Peeling a kiwi with a spoon is far easier than slicing with a knife. All it took to learn this was one web search, but it required asking myself the question of whether I was peeling fruit optimally. Same for extracting the seed from an avocado.

Cracking the shell of a hard-boiled egg, making two holes at the ends and blowing air under the membrane before peeling is another trick I wish I had known earlier.

Microwaved food is cooler in the centre, so to avoid scalding one’s mouth, it is helpful to start eating it from the middle. Cooked food left in a covered cooking pot or transferred to a storage container while still mildly hot does not go bad at room temperature for several days – doing this experiment required posing this hypothesis. Drinking without touching the bottle with one’s mouth turns out to be quite easy and is widespread in India.

Only after learning to drive did I start meaningfully using gears on a bicycle, and it took about 15 years more to start shifting approximately correctly (pedalling cadence 60-100 rotations per minute, downshifting before stopping, avoiding cross-geared riding). Similarly for basic bike maintenance like cleaning and oiling the chain, selecting the appropriate front and rear tire pressure given one’s weight and tire widths. Seat height is one thing I figured out early, but not handlebar height.

As a teenager, I would have benefited from asking myself whether I was overtraining, whether my nutrition was reasonable, how soon to return to training after various injuries and whether to seek medical assistance with these. Questioning the competence of coaches and doing a simple web search for sports medicine resources would have prevented following some of their mistaken advice.

Sometimes asking yourself the question reveals that you are already doing the task correctly. On the internet, people claim that they do not use shampoo, just water, and their hair stays clean-smelling and more lush than using detergent. An experiment not to use shampoo was a failure for me, causing greasy hair and lots of dandruff after a few days. The optimality of shampoo may depend on individual scalp and hair characteristics. On the other hand, a single-blade disposable razor and cold water give me a better shave than multi-bladed fancy brands with foam (that get clogged), and the disposable razor stays sharp enough for a month or two of everyday shaving.

When going to teach, it may be worth asking whether the room is the correct one, even if some students show up and the room is free, because once in this situation I was in a room with the right label, but in the wrong building.

On the other hand, constantly doubting oneself is unhealthy and unhelpful. If enough evidence points one way, then it is time to make up one’s mind.