Wednesday, July 27, 2011

Inflation volatility does not go up with inflation

The story used to be that inflation was bad for an economy because greater levels inflation led to greater levels of inflation uncertainty.

Uncertainty isn't exactly the same as volatility, but in practice we often equate the two when we economists do empirical work.  So, while I'm not a macro guy, a long, long time ago I wrote a paper for a graduate macro class on the link between inflation and inflation uncertainty. I just used standard time series analysis to predict inflation and then looked at my prediction error in relation to the level of inflation.  I didn't see much of a link even then.

Today I see even less of one.  To be honest, I haven't run the regressions.  I'm just looking at this picture from FRED.



Back in the seventies and early eighties we might have logically conflated levels of inflation with inflation volatility.  But today, and over the past decade, inflation has been low and inflation volatility quite high.

The real macro guys probably have a good explanation for this.  But whatever it may be, I also wonder if somewhat higher rates of inflation--say the 3-4 percent we had in the 90s, would actually be more stable.

Could this be yet another reason to have a higher inflation target?

Tuesday, July 26, 2011

Mark Bittman Embraces the Food Nanny State

Bittman, who typically writes more about food (I love his minimalist recipes) and less about food policy, fully embraces the idea of taxing "bad" food and subsiding "good" food:
....Rather than subsidizing the production of unhealthful foods, we should turn the tables and tax things like soda, French fries, doughnuts and hyperprocessed snacks. The resulting income should be earmarked for a program that encourages a sound diet for Americans by making healthy food more affordable and widely available....
He gets into details:
...Sweetened drinks could be taxed at 2 cents per ounce, so a six-pack of Pepsi would cost $1.44 more than it does now. An equivalent tax on fries might be 50 cents per serving; a quarter extra for a doughnut. (We have experts who can figure out how “bad” a food should be to qualify, and what the rate should be; right now they’re busy calculating ethanol subsidies. Diet sodas would not be taxed.)...
Maybe those experts would be the same ones who brought us the Food Pyramid.

Anyway, this does seem like the kind of thing that could get messy.  Do I really need to point to our political environment?

Something simpler, like a tax on sugar-sweetened beverages may make more sense.  At least it's specific enough to get our heads around.  Also, sugar may also be *the* culprit in our obesity/diabetes epidemic. And apparently there has been some research on it:
Much of the research on beverage taxes comes from the Rudd Center for Food Policy and Obesity at Yale. Its projections indicate that taxes become significant at the equivalent of about a penny an ounce, a level at which three very good things should begin to happen: the consumption of sugar-sweetened beverages should decrease, as should the incidence of disease and therefore public health costs; and money could be raised for other uses.
I checked out the Rudd Center and found this study(pdf).  The crux, of course, is the elasticity of demand: how much will people cut consumption of sugar-sweetened beverages if they are taxed?  That is a very difficult thing to measure.  I've never seen it done in a truly convincing way.  It must be especially difficult in the soft-drink business given the market power of Coke and Pepsi and the complex strategic pricing games they must play with each other.  Regional variation in pricing must have a lot to do with regional differences in demand elasticities; cross-sectional regressions won't work (sorry if that's a bit wonkish--economists should know what I'm talking about).

Then again, I don't really know this literature well so maybe I missed the really compelling study.

Unfortunately the paper above doesn't help much.  It simply cites other work for the crucial demand elasticity, which they pin between -0.8 and -1.2.  If the number is -1 it says consumption declines by 1% for every 1% increase in price.  This assumes  that if we increase price of a 20oz soda from $1.25 to $1.45 consumption would decline by roughly 7%, holding all else the same.

I don't know if that is reasonable or not; I'd need to follow the chain of citations a bit more and dig into modelling assumptions and identification strategies.  Experience makes me dubious that the underlying economic science is very compelling, but I am prejudging here.

But let's just suppose that's right.

The biggest challenge I see is that diet drinks wouldn't be taxed and the best way to get a large demand response would be to cause the price of sugary drinks to go up while keeping diet drink prices constant. Now, it seems to me that Bitterman (and the underlying studies) assume full pass-through of the tax on retail price.  I'm pretty sure that won't happen in reality.

In reality Coke and PepsiCo will price beverage strategically, given they have considerable market power.  Given this, I would expect the big soft drink companies to increase the price diet drinks nearly commensurately with sugar drinks, and that the price increase would fall far short of the tax amount.  That's because prices will be tied first and foremost to the elasticity of demand, not marginal cost.

To prove my point, here's an example of a similar situation: The FAA tax on airlines expired last Friday night.  You might think that the tax expiration would cause airfare to go down commensurately.  Not.  Most airlines simply raised prices to by the amount of the tax

So, even the sugary beverage tax is likely to get complicated. And I'm quite sure Coke and Pepsi won't take this sort of thing lying down.

I'm not radically against the idea of a mild food-nanny state.  But I rather imagine that this kind of thing, if passed, might be far less beneficial and have far more unintended consequences than one might initially think.

Saturday, July 23, 2011

Cotton prices tumble

Here's the story at the WSJ
Cotton prices, which surged to historic highs this spring, have plunged 38% so far this month, roiling mill owners and apparel makers.

It's a reversal for clothing makers that spent the last year grappling with higher costs and how much, if any, could be passed along to consumers. Now, retailers are wondering if lower cotton prices, off 53% since their March 4 peak, will last or if the roller-coaster ride will continue.

"There's never been this kind of volatility in cotton—ever," Eric Wiseman, chief executive of VF Corp, the world's largest apparel company, said in an interview on Thursday.

...
I guess I'd just like to note for the record that I called this one a long time ago

Maybe I just got lucky.

My juices are starting to flow for a nice long substantive post about price volatility. I should have time to write on tomorrow's travel day to the AAEA meetings.  Maybe see you in Pittsburgh.

Friday, July 22, 2011

The Latest Natural Experiment: Carmageddon

I predict: two years from now someone will present a paper in the EE session of the NBER summer institute that exploits Carmageddon as a natural experiment to estimate various acute effects of air pollution or some other consequence of reduced driving and congestion.  Maybe someone will try to extrapolate their findings to estimate the social costs and benefits of roads.

I have far less confidence that I will receive an invitation to said meetings.  Aw well...

Thursday, July 21, 2011

Cool Heat Wave Video

Heat waves are not cool.  But the video below sure is.



Original source here.

Hat tip: David Lobell.

Thursday, July 14, 2011

NOAA's 8-14 Day Temperature Outlook

Here's the picture:


Compare that to where crops are grown.



And consider that this is probably a particularly sensitive time in the growing season.

This makes me more bullish on commodity prices than the current drought map does:

Wednesday, July 13, 2011

Feeling the Heat in Kansas

Some are starting the emphasize the heat.  And they are at least acknowledging that it's really not so bad:  "...last month had been only the 26th hottest June in the past 117 years."   And while Kansas is looking pretty hot, it's often that way.  That's why it's the most irrigated state in the corn belt.  Every other corn belt state looks pretty mild and reasonably moist.  

They are forecasting a little 3-day heat wave over the next few days.  That's still a far, far cry from 1936.

So why do they have to bury reality way down on paragraph 15 or 20?

One worry about the premature, over-hyped drought stories is that when it really does get bad, everyone will yawn at the usual weather news drama. 

Tuesday, July 12, 2011

Dust Bowl II?

There's a lot more drought news these days (they gave me a quote all the way at the end of the story).  By some measures, particularly the US Drought Monitor, things look pretty bad.

But the time-series plot at the NY Times doesn't go back very far in time.  If it did, the current drought would look much less exceptional.  Also, the areas with severe drought are not very productive agricultural areas.  The Midwestern bread basket looks just fine right now.  Although the productive Mississippi Valley looks dry, crops there are irrigated, which should mitigate the damages.

Perhaps more importantly, standard drought indicators don't predict crop outcomes especially well.  I wish they'd emphasize extreme heat more than drought. I think we need our own "extreme heat indicator."  With any luck, we'll have one soon...

A larger concern could be the heat wave about to hit the midwest.  This is a bad time for extreme heat because corn plants are probably close to the flowering stage.  If it turns out as hot or a bit hotter than expected, and if that heat sticks around awhile, it will start looking real bad for corn yield.

The price volatility party is just getting started...

Renewable energy not as costly as some think

The other day Marshall and Sol took on Bjorn Lomborg for ignoring the benefits of curbing greenhouse gas emissions.  Indeed.  But Bjorn, am...