This paper reflects on a recent article by Heckman and Pinto (2013) in which they discuss a formal system, called do-calculus, that operationalizes Haavelmo’s conception of policy intervention. They replace the do-operator with an equivalent operator called “fix,” highlight the capabilities of “fix,” discover limitations in “do,” and inform readers that those limitations disappear in “the Haave...

We prove the logarithmic concavity of the Duistermaat-Heckman measure of an Hamiltonian (n− 2)-dimensional torus action for which there exists an effective commuting symplectic action of a 2-torus with symplectic orbits. Using this, we show that any symplectic (n− 2)-torus action with non-empty fixed point set which satisfies this additional 2-torus condition must be Hamiltonian.

We have used observations of the CO J = 1 → 0 transition in a sample of 20 Seyfert galaxies in order to test the result of Heckman et al. (1989), who find that type 2 Seyferts have a higher molecular gas content than type 1 Seyferts. From our observational results alone, we possibly find that L CO

Dooshanveer Nuckchady, MD; Michael G. Heckman, MS; Nancy N. Diehl, BS; Darlene Carey, RN; John Moss, MD; Tara Creech, RN; Robert Domnick; Walter C. Hellinger MD; Infectious Disease, Mayo Clinic Jacksonville, Jacksonville, FL; Biostatistics, Mayo Clinic Florida, Jacksonville, FL; Infection Prevention and Control, Mayo Clinic Florida, Jacksonville, FL; Mayo Clinic Florida, Jacksonville, FL; Infor...

A large body of literature has documented an increase in wage inequality over the 1970’s and 1980’s (see, for example, Levy and Murnane, 1992). This increase in wage inequality has occurred both within and between education-experience groups. While the former unfolds during the 1970’s, the latter is experienced over the 1980’s. Recent studies show that these trends are weakened in the 1990’s. T...

* Neumark: Department of Economics, University of California-Irvine, 3151 Social Science Plaza, Irvine, CA 92697 (e-mail: [email protected]); Burn: Department of Economics, University of California-Irvine, 3151 Social Science Plaza, Irvine, CA 92697 (e-mail: [email protected]); Button: Department of Economics, Tulane University, 6823 St. Charles Ave., New Orleans, LA 70118 (e-mail: pbutton@ tulane.e...