Difficulties in the global supply chain are a recurrent news item since the beginning of fall. The result has been that many pundits or politicians have argued for new policies that spout platitudes such as the need to “rethink trade“. For my part, all I could think of was the O-Ring theory of development developed by Michael Kremer.

The name for that theory is taken from the 1986 Challenger disaster, in which the failure of one small, inexpensive part caused the shuttle to explode upon take-off. Generally, the theory is applied to questions of development and speaks to high complementarities between inputs. Suppose the economy is divided into multiple sectors that exchange intermediaries goods between them (i.e. all firms are dependent on each other). Each of these goods can be labelled as n and producing these goods require skills q. However, each sector buys multiple different n as intermediary goods. For example, this would mean that sector “Vincent” buys goods from sectors “Joy”, “Jeremy” and “James” to produce the “Vincent” goods.

Imagine now that q is the percentage chance that n is produced with sufficient quality so that it bears its full market value (in which case, 1-q is the probability that n is produced so poorly that it gets a zero-price). This means that, to produce its goods, sector “Vincent” needs sectors “Joy”, “Jeremy” and “James” to produce high-quality goods. If one of the intermediary goods “Vincent” buys from the other is inefficient, all of Vincent’s production is worthless. Hence, the analogy to the O-Ring of the Challenger disaster.

So what’s the link with the supply chain failures you ask? Well, its pretty straightforward: the O-Ring theory implies that the impact of a bottleneck has a multiplicative effect on other productions. Now, everyone may be excused for thinking that I simply explained in a complex way something that is simple (i.e. dont half-ass things). However, this way of formulating is very helpful because of q.

If q is the probability of a badly-performed task, what determines q? Some could say its the pandemic, but that would be incorrect. An article in Nature shows that COVID-19 has yielded widely disparate effects on supply chains in different countries. If it was global, it should be roughly similar everywhere. Ergo, some local factors must be in play. Local factors of relevance would be laws on shipping such as the Jones Act in the United States or the public ownership of ports in many western countries. By preventing cabotage and limiting foreign ships, such as in the Jones Act, there is little excess capacity in the American shipping industry available when demand shocks occur. By being more bureaucratically rigid, ports may be unable to adapt to unforeseen events (which is why there are papers in transportation economics that show that privatizing ports tends to increase productivity and reduce shipping costs notably by speeding turnarounds).

Each of these local factors have to do with local policies that reduce q and tend to increase the likelihood of failures (i.e. bottlenecks) which then reverberate on total output (beyond the narrow supply chain sector). From this, I get to a simple: complications that we attribute to the COVID crisis are more likely the results of local factors.

That’s the column this week. No ad hoc economic theory, no deep insight into the profession. No silly sports talk. Just a recommendation to watch a beautiful looking and sounding movie. Allow yourself to get invested in the world they are building. Reward their willingness to be sufficiently faithful to a masterpiece while also having the maturity to know that much of the intrigue, as designed in the book, wouldn’t translate to the screen.

They’re building a world where a single commodity is so valuable, and it’s supply so inelastic, that it serves as the fulcrum for an entire galaxy. Worries about peak oil feel like fretting about a possible shortage of student selfies when compared to the economics of spice. The political economy is coming, don’t you worry. For the moment though, just take in a cool movie.

Go watch Dune.

For those who didn’t know, as part of the American Rescue Plan, there were some changes made to the Child Tax Credit (CTC) for the tax year 2021.

• First, the credit was expanded from $2k to $3,600 per child for children under 6 years of age (to $3k otherwise). It’s also fully refundable.
• Second, half of the credit is being disbursed to tax-filers early: over the latter 6 months of 2021.

What does this mean?

For context, I have 3 children all under that age of 6. My total 2021 CTC is $10,800. Half of that is being distributed as monthly checks from July through December. For me, that’s a check for $900 per month that I had not anticipated. While it is true that I will see less of a remaining credit when I file my taxes by April of 2022, I strongly suspect that most similar households are somewhat short-sighted about these funds.

Depending on the number of children in a household, the monthly check from the IRS can be quite significant. From the parent point of view, there has been a lump-sum transfer. There is no endogenous response to obtain more children – there’s no time for that. The transfer also occurs regardless of any activities, economic or otherwise. In essence, tax-filers with children have experienced a positive income shock.

The big question is: What is the effect on employment?  

In one sense, the effect is ambiguous and depends on preferences: People can now afford more leisure and more consumption. How they engage in more of each is a matter of preference. But, given that both are goods, both will increase by some amount.

That’s my simple model. I hereby make multiple predictions:

1. Parents with children will have consumed more in the 3^rd and 4^th quarters of 2021.  
2. Parents with children will have lower employment growth for those quarters.
3. The effects will be stronger for parents with children under 6 years of age.
4. The employment rebound in the 1^st quarter of 2022 will be stronger for these groups (and stronger than forecasted overall).
5. Finally, while I’m feeling silly enough to make predictions publicly, I predict slower growth in consumer durable expenditures in 2022 Q1.

I looked at the BLS for data to corroborate my predictions. Excitingly, the Current Population Survey (CPS) does slice the data by sex, age, and age of own children (conveniently by younger than 6 and 6-17 years of age). This is where I post the great visual to demonstrate the veracity of my claims, right?

WOMP WOMP.

The relevant data is currently only available annually as recent as 2020…

Grade inflation in the US education system is a common observation, one that is, at least at the college level, largely undeniable. A couple recent interactions with students has brought it to the front of my mind again. When discussing their majors and what classes they were taking, there was considerable hesitation to take what were perceived as difficult classes. What I thought this called for, in the moment, was a bit of confidence building, for a professor such as myself to say “You can do it!”

It turns out confidence in their ability to learn the material was not the issue. What they were unsure of was their ability to get an A. No, to guaranteed get an A. It was the risk of a sub-A grade that concerned them (likely exacerbated by the fact that my university does not award + and – grades in undergraduate classes). So I went through my usual pitch:

You take 5 classes a semester for 8 semesters. That’s 40 classes. The cost of couple B’s or even a C will pale in comparison to the benefit acquiring more technical skills, which would pay out for a lifetime. A couple courses in computer science, econometrics and statistics, maybe real analysis for those thinking about a PhD in economics – these would all have huge payoffs. There was a problem with my logic, however, that quickly became apparent.

They weren’t sure what they wanted to do after their bachelors. They didn’t know what advanced degrees they might pursue, whether law or medical school was something they were interested in. What they did know, however, is that GPAs were really important. That students were applying to things they might be interested in, and doing so with 3.8 and 3.9’s. When they saw classes that regularly handed out C’s (not D’s or F’s mind you, just C’s), what they saw was pure downside risk. If they were great at something, no one would ever be able to tell. But if they weren’t, or if they had a bad day on a hard final exam, that it could close doors. What I inferred was that they were trying to maximize their expected outcomes, and in order to do so they had to minimize the number of hard classes in their portfolio. Each path had a handful of unavoidable hard classes, so to take a an additional hard class beyond the requirements of the path they chose was suboptimal.

I don’t know that they’re wrong.

I’ve told this story before. When I was considering getting a PhD in economics I planned on just going to my local school. I was visiting a friend on the opposite coast, though, and thought I’d stop in at a really good local school there. I met with the director of graduate studies in the economics department and was flatly informed that my application would not be read because my GPA (3.2, if you’re curious) was below their cutoff. I said thanks and left. It was some time later that it dawned on me that this was ludicrous. Did they simply never admit students from (the famously uninflated grades of) CalTech? Were they discriminating against math and engineering majors? Likely not. But this is deeper knowledge than that held by your typical undergraduate. All they know is the average admissions statistics and the implied (or in my case explicitly stated) cutoffs.

When we inflate grades and get rid of standardized tests, we put greater pressure on students to curate their education to expected grade outcomes and, more important, to minimize risk. There’s no upside to shining in a difficult class if the best 50% all get A’s. The signal value of success has been attenuated. The signal value of failure, however, has not just been left intact, it’s been heightened. There’s no positive variance to balance it out. There’s no way to be an excellent B+ student whose occasional C in risky classes are balanced out by some exemplary A’s. We’ve effectively raised the costs of taking challenging classes and in doing so discouraged students from acquiring the skills that are most rewarded in the marketplace.

The problem only becomes all the worse when we think about the cultural biases in the confidence we cultivate in different groups of students. If a deficiency in math and science has been low-key implied at every stage of your education, you’re that much less likely to incur the risk of “hard classes”. There’s much pearl-clutching over “everyone winning a trophy” and school being too easy from folks who walked to and from school through 12 months of snow, uphill both ways. Those arguments, which are often little more than a sort of grumpy money illusion, miss the real problem entirely. Undoing grade inflation to make school harder is like giving 7 points for every goal in soccer to make it more exciting.

The actual grades don’t matter. What matters is the the shape of the distribution of grades . If we bunch everyone in the A’s and then disproportionately select into institutions based on those grades, we’re incentivizing students to stay in the herd. To risk your GPA for the sake of hard classes is to risk being isolated. To risk being cutout by admissions committees trying to sort through 1000 applications, half of with have near-perfect GPA’s, and for whom the fastest way to make their workload manageable in an acceptable manner is cut out everyone with less than 3.7.

I’m not sure students are wrong in their grade-mongering. They got into college in many cases based on nothing but those GPAs. They’ll be able to go to grad school without taking the GRE. There will come a day, however, when the next step isn’t school, and after which no one will ever ask them their GPA again for the rest of their life. After which the only thing that will matter is what they know. And who will know more: the overconfident student of upper-middle class parents who graduated with a 2.8 BS in electrical engineering or the pragmatic student who curated courses to maximize their 3.7 GPA while preparing for the MCATS and medical school? I don’t know who will leave with more skills, but I also don’t worry about either. Who I worry about is the first-gen college student, the child of a working class household with a 4.0 BA and 4.0 MA in communications who, desperate to prove to others that they belonged in school, made sure to protect that perfect GPA at every turn. What have we done to ensure that they know enough when they enter the job market?

Upfront: I’m totally replying to a meme.

I sympathize with the sentiment of the meme. But friends of friends were quickly critical of it. Then I wasn’t sure what to believe. So, I crunched the numbers.

First of all, there is an inherent ambiguity in the meme’s claim, seeing as future tax rates, maximum taxable income, benefits, and plausible returns are unknown. But we can address the data so far. The meme is dated in 2019, but current data is even more charitable toward it.

What we know as of 2021:

The maximum annual benefit is currently $46,740. It was previously lower, but this is a charitable post.

We also know the historical tax rates and maximum taxable incomes. Currently, 12.4% and $142,800. YES, we’re about to assume that somebody met the maximum income criteria over their entire working life.

If someone worked for 40 years while making the maximum contribution each year, then they would have contributed $406,255.20. If we plainly calculate the rate of return on this amount, then we’d yield 11.5%, which is not too shabby ($46,740/$406,255.20). Of course, this is entirely unreasonable because the funds could have been earning interest in private hands during the contribution period. If the funds had been earning 5% throughout the entire period, then the 2021 value of the contributed funds would be $968,838.39. The annual benefit implies a return of 4.8% ($46,740/$968,838.39). Investing those funds in a private account that yielded 5% would have provided $48,441.92 per year, which is not a huge difference. In this light, social security appears not to be a terrible deal. Not as good as the private sector – but not far off.

Let’s be more charitable to the spirit of the meme. What about for 50 years of work? Then the total contribution would have been $423,905.38, yielding an implied return of 11%. Considering the time value of money changes the rate of return to 4.2%. Again, not terrible, but now noticeably less than 5%. If the funds had been invested at and paid out 5%, then the private annual benefit would be $55,846.56. In other words, the privately invested funds would have yielded an annual benefit that is 19.5% higher than what is currently paid. That is substantial. The social security investment is definitely not excellent.

How reasonable is the meme? Well, in order to get the $1.9M figure, interest rates would have to be 7.2% (assuming 50 years of work and that we don’t spend the principal). The concomitant annual retirement benefit would be $136,825.51 (Now that’s an exciting number). In order to get the $95k, we only need to assume 6.3% per year. The S&P 500 has yielded an annual return of 7.6% over the same period (not including dividends). The meme is reasonable. Not perfect. But not ridiculous.

One BIG caveat is that this entire analysis assumes that the employee could simply invest equivalent amounts if Social Security were abolished. This is very unreasonable. Currently, part of the contribution comes from employers. While employees would experience an increase in total pay if the taxes were abolished, the employer would also enjoy a lower cost of labor. Not all of the gains would go to the employee.  One could also argue that abolishing Social Security would improve growth and real incomes generally, but that’s a counter-factual beyond the scope of this post.

Here is the sheet where I show my work.