Chapter dzǵ: Tacit Preachments are the Worst Kind ȁȂȆIn the same journal issue, Steve Williamson and Randall Wright
(ȀȈȈȃ) explain how money, besides providing its familiar services, cuts
down the information requirements of exchange, giving transactors a bet-
ter chance than they would have under barter to wind up with high-quality
goods. Ļe authors’ model assumes away the noninformational difficulties
of barter, leaving no role for money in the absence of private informa-
tion. Time is discrete and goes on forever. Ļe population is a contin-
uum of immortal agents who can produce both good and bad commodi-
ties at positive and zero utility cost, respectively. Consumption of money,
of a bad commodity, or of one’s own output yields zero utility, while
consumption of someone else’s good output does yield utility. Detailed
assumptions about proportions of good and bad commodities, probabili-
ties of encounters, and so forth create the opportunity for numerous equa-
tions and graphs adding nothing to the central message, as far as I can
see, except spurious rigor. Ļe authors give no reason for supposing that
what is rigorously true of their concocted world is equally true of the real
world.
Robert Frank has done much insightful writing at the intersection of
economics, psychology, and ethics. His article ofȀȈȇȆ, however, provides
an example of the merely decorative use of mathematical code, as distin-
guished from bona fide manipulation requiring symbols. One footnote
(ȀȈȇȆ, p.ȄȈȄ) even promises “a more reader-friendly version” of his model
in a then-forthcoming book. Well, why wasn’t he friendly to his current
readers? Bénassy’s article ofȀȈȈȂ, which I admire for its actual substance, is
similarly discourteous in its use of symbols. Bénassy actually distinguishes
between certain concepts by whether the identical double-subscripted let-
ters representing them are topped by a macron or by an only slightly wavy
tilde; this is a subtlety likely to escape a reader not wielding a magnifying
glass. I suspect that he, like Frank, Ireland, and Williamson and Wright,
was bowing to tacit methodological pressures.
As Mayer’s strongest-link (or most-rigorous-link) principle suggests,
a display of technique can plaster over much. Robert Solow was stay-
ing within the bounds of permissible exaggeration when he wrote (ȀȈȇȄ,
p.ȂȂǿ) that a modern economist, dropped with his computer from a time
machine into any old time and place, will soon
have maximized a familiar-looking present-value integral, made a few
familiar log-linear approximations, and run the obligatory familiar regres-
sion. Ļe familiar coefficients will be poorly determined, but about one-
twentieth of them will be significant at theȄpercent level, and the other