If this is true (I believe this is likely to be the case), we should invest vastly less in education than we currently do. Rather than trying to find good teachers, we should just aim for the cheapest warm bodies we can find, not to mention speeding up the process (e.g., graduate at 14).

This belief lies behind the signalling model of education - education adds little value but signals to employers that value was already present.

I actually had two chemistry teachers in high school who fit this description. The first was a drunk that they hired off the street (seriously, the administration not believe us until we found an empty whiskey bottle in the back cupboard). They replaced her the second quarter with a flighty woman who didn't understand the material and regularly lost our assignments and tests; some time after they fired her I saw an article in the variety section of the local paper showing her in her home, back to the camera, with her hands on her hips staring at the massive pile of junk in her house—it was an article about ADHD adult packrats. For the final quarter they put us in a real chemistry teacher's class, where none of us were at all prepared having learning nothing for the first 2/3rds of the year, and they had to just give us the credit for the year.

The point of this anecdote is that there were plenty of smart, motivated students in this class, but the teachers made it impossible to learn, so the performance of everyone was equalized to the lowest common denominator. The only people who learned anything were the ones willing to read the book for its own sake without any guarantee of proper labs or tests. The next year I got into the physics class of a teacher who was widely regarded as the best in the school. We learned a lot in that class, but even there you had problem kids who refused to make any effort, despite the fact that the teacher clearly cared about the students; they saw him as someone to be taken advantage of.

So you see, neither factor stands alone. You need decent teachers, and you need kids to show up.

ZachPruckowski and RyanMcGreal seem to be claiming that variation in teaching methods has little effect on achievement, and demographics/non-school factors seem to be the major cause of variations in achievement. If teaching is not a major cause of achievement, we should not waste time and money on it. Similarly, we should not waste time and money on shark repelling sticks or homeopathy.

But I should point out that the anecdote you repeat seems to imply that teachers don't have a particularly large effect on achievement. As you say, "even there you had problem kids who refused to make any effort" and you had "the ones willing to read the book for its own sake". The teacher won't help either of these categories of student very much. Supposing, for the sake of argument, that these two types of students make up 2/3 of the class, and a good teacher can improve the grades of receptive students by 20% over a crappy one, then teacher quality only accounts for 6% of the achievement of the class.

Then there's the Hierarchy of Needs issue. Before you can really learn and grow and develop, you have to fulfill your basic needs. If you're starving, then the only fractions you're able to focus on are fractions of a sandwich.

By the way, no one in America (besides anorexic rich girls) is starving. Gluttony is the only food-related problem faced by the poor, starvation hasn't existed for a while.

This absolutely not true, some students only meal of the day comes in school with reduced or free lunch. Not every poor kid is accustomed to nothing but what McDonald's serves.

So you're suggesting we abandon schooling altogether, and just let all those kids wander around unable to read?

>Gluttony is the only food-related problem faced by the poor, starvation hasn't existed for a while.

Would it were so.

http://www.learnmoreindiana.org/needtoknow/pages/valueofeduc...

As you say, education can increase achievement by 10-20%. Supposing we can get a 20% improvement in graduation rates, that would only be worth $57k/student to the population of future high school dropouts (and it would slightly harm those who don't dropout, but I'll ignore that). A quick google search suggests that about 8% of students drop out.

http://nces.ed.gov/fastfacts/display.asp?id=16

$57k x 20% x 8% = $900 (per student, over K-12).

If we spend more than $900 to increase graduation rates by 20%, we are wasting our money. If we could reduce dropout rates to 0%, it would be worth $22.9k/student (again, over 12 years).

[edit: fixed calculation.]

The point that the article is making is that it damages the argument against teacher union lock-in to observe that the best teachers in the public school system can only produce a 10-20% bump, because it implies that the free-market hiring practices of charter schools won't solve the core problem. Meanwhile, 50% of all teachers, including (one assumes) several good ones, are leaving the profession early because conditions suck.

Suppose a student costs $8k/year. If spend 3x more to reduce dropout rates to 0%, and we achieve the hypothesized increase in income, we are wasting $170k per student (i.e., we are spending an extra $192k to avoid a $22k loss).

This also assumes that the educational buckets are "drop out, high school, college, and advanced degree". What do you think happens if we substitute "college" with "trade school"? What percentage of students will learn a formal trade if they complete high school that wouldn't if they had to get a GED first?

You also ignore the externalities of high school drop-outs; for instance, what percentage of high school drop-outs end up in prison? Note also that juvenile prisons are spectacularly more expensive than adult prisons. Are you hoping to stipulate that the burden to society of supporting drop-outs is wash against the competitive advantages given to people who complete school?

Also, I suspect that yes, the benefits of having these people graduate high school is a wash. Currently, a high school degree is a signal that you are not dealing with the utter dregs of society and that the student can do what they are told for 12 years. If we spend $16k/year graduating everyone, a high school degree will be a signal that if an employer is willing to devote $16k/year to supervising the employee, they might be able to get some useful low skill labor out of them.

As for your theory of poor kids dropping out and then going bad/getting arrested, it just doesn't fit my experience. At the school I dropped out of, the kids were carrying metal long before they dropped out, and there was nothing that Dangerous Minds could do for them.

Look, I haven't worked out all the numbers. I've just a feel for the orders of magnitude. If you want to "spend 3x more", we will spend more on education than we spend on SS, Medicare and the military combined. I don't see any remotely reasonable way that the benefits would exceed this cost. But feel free to post your own numbers.

[Edit: just noticed I used a slang term. "Dangerous Minds" is a mocking term for nice liberal white girls trying to save their students. http://www.imdb.com/title/tt0112792/ (Also usable as a verb.)]

However, we may need to triple what we're spending to teach kids in Englewood, or Harlem, or Oakland.

If we could add 100-200bn to education spending to triple the resources allocated to the bottom 10% of school systems, that might very well be worth it: those students are disproportionately likely to benefit from that spending, earn hundreds of thousands of dollars more throughout their life, secure jobs that include health insurance, avoid expensive prison terms, and draw less on welfare.

- Good teaching does make a huge difference. A large amount does get washed out due to other factors, but that doesn't mean it would make sense to purposely hire 'warm bodies'.

- Good teachers don't necessarily cost more than bad teachers.

- Teachers salaries are only a small part of school spending. I don't know the exact numbers, but my guess would be 30% of the annual district budget, which IIRC wouldn't include extraordinary expenses.

- Schools aren't the only component of education. There's also early childhood education, libraries, community colleges, etc.