More on F versus t tests for unit roots when there is no trend

Rodrigues and Tremayne (2004) interpret a problematic size result in a Monte Carlo study reported in Elder and Kennedy (2001) as arising from Elder and Kennedy's use of an inappropriate testing equation. In expositing their result, Rodrigues and Tremayne inadvertently lead readers to believe that the Elder and Kennedy conclusion is in error. We clarify the Rodrigues and Tremayne contribution, putting the validity of the Elder and Kennedy result in proper perspective and underlining the important role played by the starting value in Monte Carlo analyses.

F versus t tests for unit roots

F tests which test jointly for a unit root and a zero intercept, and so compete against Dickey-Fuller t tests, are shown not to enhance power because they are invariant to the intercept value in the absence of a unit root. Monte Carlo results in the literature that indicate otherwise are shown to have resulted from the use of special starting values. Testing procedures that employ these F tests to enhance power should be revised.Dickey-Fuller

SSI for the Aged and the Problem of 'Take-Up'

The Supplemental Security Income (SSI) program provides an income and health care safety net for the elderly poor. The phenomenon of apparently eligible households that do not enroll in, or 'take up' SSI has been noted as a severe problem since the program's inception in 1974. This paper examines SSI eligibility, applications, and participation in the aged population from 1984 (the most recent year analyzed in the literature to date) through 1997. We are fortunate to have administrative data on SSI use that is linked to various panels of the SIPP. We use this information to estimate the SSI-aged application choice. The key findings from the earlier literature are sensitive with respect to exact sample specification, alternative approaches to imputing the expected SSI benefit, and more detailed information on application and receipt culled from administrative files. Our findings suggest that cash benefits may be less influential, and Medicaid access through SSI more influential, than previously estimated.

An experimental model of a 2kw, 2500 volt power converter for ion thrustors using gate controlled switches in two phase-shifted parallel inverters summary report

Power converter for ion thrustors using electronic gate controlled switches in two phase-shifted parallel inverter

Patterns theory and geodesic automatic structure for a class of groups

We introduce a theory of "patterns" in order to study geodesics in a certain class of group presentations. Using patterns we show that there does not exist a geodesic automatic structure for certain group presentations, and that certain group presentations are almost convex.Comment: Appeared in 2003. I am putting all my past papers on arxi

On trivial words in finitely presented groups

We propose a numerical method for studying the cogrowth of finitely presented groups. To validate our numerical results we compare them against the corresponding data from groups whose cogrowth series are known exactly. Further, we add to the set of such groups by finding the cogrowth series for Baumslag-Solitar groups $\mathrm{BS}(N,N) =$ and prove that their cogrowth rates are algebraic numbers.Comment: This article has been rewritten as two separate papers, with improved exposition. The new papers are arXiv:1309.4184 and arXiv:1312.572

Sling: “Richter der letzten Instanz”

In the 1920s courtroom reportage became an important journalistic genre in the 1920s as leftist and liberal reporters filed into the halls of justice and analyzed what they saw and heard there in order to expose the injustices of a judicial system that had not embraced the liberal republic. Paul Schlesinger, who wrote under the pseudonym Sling, along with his colleagues Carl von Ossietzky, Kurt Tucholsky, Gabrielle Tiergit wrote of the sensational and the mundane, the political and the everyday cases, all of which provided the basis for social commentary and political criticism. Some have argued that the eagerness of these journalists to criticize the German judicial system helped to foster a “crisis of confidence” in the German judiciary - a factor that contributed to the undermining of Weimar democracy. Others, like Claudia Schönigh, have argued that the reportage of Sling and others offered constructive suggestions for the liberalization of the German justice system and that these suggestions remained unheeded by an intransigent judiciary