Did our message finally get through? (See “How ADA-for-the-Web Regulations Menace Online Freedom,” 2013). Or that of other commentators like Eric Goldman, who warned (of a related court case) that “all hell will break loose” if the law defines websites as public accommodations and makes them adopt “accessibility”? At any rate, the U.S. Department of Justice, after years of declaring that it was getting ready any day now to label your website and most others you encounter every day as out of compliance with the ADA, has suddenly turned around and done this:

In an astonishing move, the Department of Justice (DOJ) announced that it will not issue any regulations for public accommodations websites until fiscal year 2018 — eight years after it started the rulemaking process with an Advanced Notice of Proposed Rulemaking (ANPRM).

Yes, eight years is a very long time for a rulemaking, especially one pursuing issues that have been in play for many years (that link discusses testimony I gave in 2000). And predictably, some disabled interest-group advocates are already charging that the latest delay is “outrageous” and shows “indifference.” More likely, it shows that even an administration that has launched many audacious and super-costly initiatives in regulation has figured out that this one is so audacious and super-costly that it should be – well, not dropped, but left as a problem for a successor administration.

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In the past two decades, much scientific research has been conducted to examine the uniqueness (or non-uniqueness) of Earth’s current climate in an effort to discern whether or not rising atmospheric CO₂ concentrations are having any measurable impact. Recent work by Thapa et al. (2015) adds to the growing list of such studies with respect to temperature.

According to this team of Nepalese and Indian researchers, the number of meteorological stations in Nepal are few (particularly in the mountain regions) and sparsely distributed across the country, making it “difficult to estimate the rate and geographic extent of recent warming” and to place it within a broader historical context. Thus, in an attempt to address this significant data void, Thapa et al. set out “to further extend the existing climate records of the region.”

The fruits of their labors are shown in the figure below, which presents a nearly four-century-long (AD 1640-2012) reconstruction of spring (Mar-May) temperatures based on tree-ring width chronologies acquired in the far-western Nepalese Himalaya. This temperature reconstruction identifies several periods of warming and cooling relative to its long-term mean (1897-2012). Of particular interest are the red and blue lines shown on the figure, which demark the peak warmth experienced during the past century and the temperature anomaly expressing the current warmth, respectively. As indicated by the red line, the warmest interval of the 20^th century is not unique, having been eclipsed four times previous (see the shaded red circles) in the 373-year record – once in the 17^th century, twice in the 18^th century and once in the nineteenth century. Furthermore, the blue line reveals that current temperatures are uncharacteristically cold. Only two times in the past century have temperatures been colder than they are now!

Figure 1. Reconstructed spring (March-May) temperature anomalies of the far western Nepal Himalaya, filtered using a smoothing spline with a 50 % frequency cut off of 10 years. The red line indicates the peak temperature anomaly of the past century, the blue line indicates the current temperature anomaly, the shaded red circles indicate periods in which temperatures were warmer than the peak warmth of the past century, and the shaded blue circles indicate periods during the past century that were colder than present. Adapted from Thapa et al. (2015).

In light of the above facts, it is clear there is nothing unusual, unnatural or unprecedented about modern spring temperatures in the Nepalese Himalaya. If rising concentrations of atmospheric CO2 are having any impact at all, that impact is certainly not manifest in this record.

Reference

Thapa, U.K., Shah, S.K., Gaire, N.P. and Bhuju, D.R. 2015. Spring temperatures in the far-western Nepal Himalaya since AD 1640 reconstructed from Picea smithiana tree-ring widths. Climate Dynamics 45: 2069-2081.

An editorial in today’s New York Times calls for a financial transactions tax – a tenths of a percent charge on the market value of every trade of a stock, bond, or derivative. My Working Papers column two years ago described the pitfalls of such a tax.  While tax rates in the range of tenths of a percent sound small they would have large effects on stock values.  Bid-ask spreads are now 1 cent for large cap stocks. A 0.10 percent tax would add 5 cents to the spread for a $50 stock.

The alleged purpose of such a tax is to reduce the arms race among High Frequency Traders who exploit differences in the timing of bids and offers across exchanges at the level of thousandths of a second to engage in price arbitrage.  In the Fall 2015 issue I review a paper that demonstrates that this arms race is the result of stock exchanges’ use of “continuous-limit-order-book” design (that is, orders are taken continuously and placed when the asset reaches the order’s stipulated price). The authors use actual trading data to show that the prices of two securities that track the S&P 500 are perfectly correlated at the level of hour and minute, but at the 10 and 1 millisecond level, the correlation breaks down to provide for mechanical arbitrage opportunities even in a perfectly symmetrical information environment.  In a “frequent batch” auction design (where trades are executed, by auction, at stipulated times that can be as little as a fraction of a second apart), the advantage of incremental speed improvements disappears. In order to end the arbitrage “arms race,” the authors propose that exchanges switch to batch auctions conducted every tenth of a second.  No need for a tax.