Isaac Sorkin and Henry Swift give us some good reasons to procrastinate:

Though work-smoothing may sound appealing, we all know that it never happens to the ideal degree.  Part of this is certainly due to decision-making myopia.  But is it possible that there is also a rational component to our procrastination habits?  There are at least three reasons why this might be the case.  The first is that there are fixed costs to doing homework.  Suppose that in order to do homework you have to run to Kohlberg for a mocha latté…and check your favorite five media outlets as a preemptive distraction.  In that case, it makes sense to have longer homework sessions in order to reduce the total number of sessions (and number of fixed costs to pay).  Thus, putting things off in order to concentrate the work for a paper in one epic block means that you don’t have to waste time setting up to write again and again.

The second reason is that there may be decreasing marginal costs to doing homework.  Suppose that the second hour of doing homework is much easier than the first, and the third easier yet and so on.  You get in the homework zone.  Then it makes sense to make your homework sessions as long as possible in order to take advantage of these returns to scale in doing homework…

The third reason is that there might be “thick-market externalities” in doing homework.  The idea is that if everyone else is doing the same thing that you are, it gets easier and more enjoyable.  If all of your friends are procrastinating at the same time, then the opportunity cost of doing work is that you miss an excruciatingly funny episode of “Curb Your Enthusiasm”…  Similarly, when everyone is doing work, the opportunity cost of work is very low.  After all, “Curb” is far less excruciatingly funny when watched alone.  So it makes sense to do work when your friends do work, and avoid work when your friends avoid work.

Perhaps they should have been taxed for having written this.  Fortunately I am a reverse procrastinator and I have no problems with these issues.  It is procrastination which I put off, not work.

Arnold Kling discusses Dasgupta, Stern, and de Long.  Here is his bottom line:

My concern is with Stern, Dasgupta, or DeLong playing social engineer and picking a social discount rate that deviates from market interest rates.  I think you get unreliable conclusions any time you do that.

I’ll recap my views as follows:

1. For resources which will be reinvested, use the rate of return on capital, adjusting for taxes, risk, and the like.

2. For resources which will otherwise be consumed within the current generation, use the market rate of interest, again with adjustments.  That rate reflects time preference within a life.

3. If we are comparing different consumption units across the generations, there is no time preference in the economically meaningful sense.  (Prior to 1962, I was not impatiently waiting to have been born.)  Use zero, noting this is an ethical rather than economic choice.

Depending on the configuration of the variables, the correct "net" discount rate usually will be above zero but below the current market rate.

Note that the future consumption/investment ratio is not a current fact about the world, but rather a matter of choice.  That means the correct discount rate is also not a "current fact about the world," but rather will depend on other choices we make.  This is a common confusion.

Arnold also writes:

Even if the Stern report had nothing to do with global warming, its assumption for the social discount rate has radical policy implications. Implicitly, it argues for an all-out effort to reduce private-sector and public-sector consumption and to increase investment instead.

I am less worried.  Not all or even most current consumption reductions will much benefit the next generation.  (Does anyone know what percentage of a marginal increment of savings ends up in bequests?)  The prospect of current consumption is also a (the?) driving force behind innovation and technological improvement, which most definitely  benefits future generations.  We should invest more in the future, but the intergenerational zero rate view, correctly interpreted, does not require that we should limit consumption as much as possible.

Addendum: Here is commentary from The Economist.

In Naftalan you can buy a bath in pure crude oil.

Tim Harford asks whether it is efficient to have the Christmas decorations go up earlier each year.  Partly for traditional and aesthetic reasons, he would prefer a shorter Christmas season. 

In my basic model, suppliers with P > MC put up decorations to stimulate more buying and gift-giving.  Bringing on Christmas early is a form of associative advertising.  A shorter Christmas season would mean less overtime work, less spending (more saving), and spending spread more smoothly throughout the year.

What’s the benefit of having all that consumer spending clumped together at Christmas season?  I can think of three hypotheses:

1. It yields "thick market" externalities, such as allowing people to do most of their shopping when inventories are highest.

2. It yields a "do or die" season, in which new products can be rapidly and ruthlessly evaluated.  Don’t we already have the verdict on Zune?

3. Suppliers are inefficiently "fishing" for early "capture" of consumers as part of a common pool problem.  If a given supplier doesn’t grab that consumer’s attention now, someone else will.  Of course there can be no property rights in "the attention of consumers," so that attention is consumed inefficiently early.

I believe in #1, #2, and #3, but I suspect #3 is the operative force, leading me to side with Tim.  Christmas is fun, but perhaps we have just a little too much of it.

For decades, the fiercely independent fruit and vegetable growers of
California, Florida and other states have been the only farmers in
America who shunned federal subsidies, delivering produce to the tables
of millions of Americans on their own.

But now, in the face of tough new competition primarily from China,
even these proud groups are buckling.  Produce farmers, their hands
newly outstretched, have joined forces for the first time, forming a
lobby group intended to pressure politicians over the farm bill to be
debated in Congress in January.

Most of the current $15 billion in direct subsidies goes to five commodities: corn, cotton, rice, wheat and soybeans.  Now Chinese garlic sells for about half the wholesale price of American garlic.  One garlic manager commented:

“The Chinese garlic totally caught us off-guard and knocked us down,”
Mr. Mantelli said recently as he checked on newly planted garlic bulbs.
“I think our industry has hit rock bottom.  Maybe now we can figure out
how to make it a level playing field.”

Here is the full story.