The Cornerstone report notes the following findings:

1. Cornerstone reports that there were 166 securities class action lawsuit filings in 2007, which represents a 43% increase over the 116 filings in 2006. The 2007 yearly total is, however, 14 percent below the average for the ten-year period ending in December 2006.
2. Stock market volatility is important in explaining the number of filings. The increase in filings in the second half of 2007 coincided with an increase in volatility in the U.S. stock market from the historically low levels that prevailed in 2006 and the first half of 2007.
3. Securities lawsuit filings as a percentage of the total number of publicly traded companies increased in 2007. 2.19% of publicly traded companies were sued in securities lawsuits in 207, compared to only 1.57% in 2006, and by contrast to the 2.27% ten-year average from 1997-2006.
4. For cases filed in 2007, the drop in market capitalization both from the beginning to the end of the class period and from the class period high to the end of the class period increased, largely driven by several large case filings in the fourth quarter of 2007.
5. Of the 2,646 cases in Cornerstone’s database, 81 percent have been resolved. Of the resolved cases, 41 percent were dismissed and 59 percent settled. For the cases filed from 1996 to 2001, almost all of which have been resolved, the median time to resolution is 33 months. The median time to dismissal is 25 months, and the median time to settlement is 36 months. Cases with larger shareholder losses are likely to take longer to resolve.
6. The Finance sector had the largest amount of litigation activity, with 47 Finance cases in 2007, driven by the subprime crisis.
7. The top three Circuits in terms of the number of 2007 filings were the Second Circuit, with 58 filings; the Ninth Circuit, with 39 filings; and the Eleventh Circuit, with 18 filings.
8. Cornerstone counted 32 cases attributable to the subprime crisis (by contrast to my own count of 34 cases, here). The report notes that the subprime filings reflect a shift in emphasis from allegations related to traditional income statement line items to allegations related to balance sheet components.

In attempting to discern the significance of the 2007 filing levels, the Cornerstone report revisits the analytic framework Cornerstone first postulated in its mid-year 2007 report (here). The mid-year report raised two alternative theories for the lull in litigation activity from mid-2005 to mid-2007, the "less fraud" hypothesis and the "lower volatility" hypothesis. The "less fraud" theory, associated with Stanford Law Professor Joseph Grundfest, involved the theory that as a result of corporate reforms, there is less fraud and hence less litigation. (Professor Grundfest went further and speculated that perhaps, as a result of the reforms, there had been a "permanent shift" to a lower litigation level.) The "lower volatility" theory noted that the period of lower litigation activity coincided with historically low stock market volatility, and speculated that litigation activity might return to historical norms if volatility returned.

The year-end Cornerstone report expressly attributes the increased litigation activity in the second-half of 2007 to the heightened level of stock market volatility during that period. Nevertheless, the report also states that "the ‘less fraud’ theory suggests a significant and permanent shift in the class action landscape" that is "not inconsistent with the recent increase in filing." The report finds this possibility because of the significant amount of 2007 litigation activity that was directly associated with the subprime crisis, which the Cornerstone report describes as "a likely ‘one time’ event," that "may not be indicative of future filing activity."

To support this analysis, the report suggests that there is an identifiable "core litigation rate," which is a statistical construct based on historical filings from which "one time events" like "backdating, subprime cases [and] IPO Allocation filings are excluded." Using this construct, the report finds that "litigation activity remains well below historical norms." Professor Grundfest describes this "core litigation rate" as "the litigation rate observed net of one-time systemic shocks."

I cannot disagree with the report’s overall conclusion that more data is needed before the "less fraud" hypothesis can be conclusively rejected. Indeed, only time will tell. But for a number of reasons, I disagree with the Cornerstone Report’s analysis of the 2007 filings, and in particular with the report’s conclusions about the significance of the 2007 filing activity.

First, the Cornerstone report treats the 2007 subprime litigation activity as if it consists of a single, uniform phenomenon, limited in scope and duration. But my own view is that even though the subprime meltdown is still relatively recent, the litigation activity has already evolved into a highly diverse set of circumstances, lawsuits and litigants. As I detail at greater length here, the subprime litigation wave already involves a wide variety of kinds of companies and allegations. Moreover, it is likely to continue to evolve in the months ahead. To isolate the subprime cases as if they represent a narrow or contained phenomenon minimizes the potential of the ongoing subprime litigation wave to drive litigation activity for months and perhaps years to come, and disregards the very real possibility that the wave will expand to encompass a far wider variety of litigants and allegations.

Second, even if the subprime litigation wave can fairly be characterized as a "one-time" event, that is hardly sufficient to marginalize its continuing significance. The fact is the world of D & O liability has experienced a steady progression of "one time events" in recent years — the bursting of the Internet bubble, the telecom crash, the IPO Allocation cases, the corporate scandals, the options backdating cases, and now the subprime crisis. Indeed, the joke among D & O insurance industry professionals at the recent PLUS International Conference was that subprime is "just a one time event" – the joke being that in the D & O industry, there is a one time event every year, and that results are driven by the constant recurrence of supposed "one time events." When one time events become the norm, they are not extraneous, they are the very essence of the risk exposure.

The reality is that the claims experience in the D & O arena is characterized by a succession of one time events. Indeed, no D & O insurance manager who wished to retain his credibility with senior insurance company management would attempt to try to marginalize the subprime litigation wave by describing it as a one time event, simply because there have been too many supposed one time events in recent years for the phrase to retain any meaning. D & O claims are and for years have been driven by these kinds of events. There perhaps may be a statistical construct by which to postulate a "core litigation rate," but the construct would be disregarded by insurance professionals as lacking credibility and unlikely to provide adequate predictive power to describe likely future events. The practical reality is that it must be assumed that there will always be one time events – not as unusual occurrences, but in the ordinary course.

Finally, as I have documented elsewhere (here and here), subprime litigation is only one of a number of important factors driving the recently increased litigation activity. Even without the subprime cases, the uptick in litigation activity is significant.

To be sure, only time will tell whether the increased litigation activity in the second-half of 2007 is indicative of future activity levels. But as I previously stated (here), I think there is already a sufficient basis upon which to declare that the two-year lull in securities lawsuit filings is over, and to state that there does not appear to have been a "permanent shift" to lower securities lawsuit filing levels.