Lucas on blueprints as physical capital

In my Mathiness article, I refer to this quote from Lucas (2009):

Some knowledge can be ‘embodied’ in books, blueprints, machines and other kinds of physical capital, and we know how to introduce capital into a growth model, but we also know that doing so does not by itself provide an engine of sustained growth.

Ask yourself these three questions:

1. Which logical quantifier on the set of models does Lucas need to insert before “doing so does not …”  to make the clause that follows the conjunction “but” true?

a) for all models

b) there exists a model in which

Hint: Search for articles in economics journals that contain both “blueprint” and “endogenous.”

2. If we did a field experiment and asked readers to interpret this sentence, which quantifier would most of them would infer?

a) for all models

b) there exists a model in which

3. What fraction of these readers would be aware after reading the sentence of the sensitivity of the meaning of the sentence to the choice of the unstated quantifier?

It is a small but instructive example of how someone can use mathiness (i.e. slippage between words and math) to obfuscate and mislead whilst pretending to make use of the clarity of logic and math.