Photons from axial-vector radiative decay in a hadron gas

Strange and non-strange axial-vector meson radiative decays contribute to photon production in hadron gas. One- and two-hadron radiative decay modes of $b_{1}(1235)$, $a_{1}(1260)$ and $K_{1}(1270)$ are studied. At 200 MeV temperature and for a narrow range in photon energies they contribute more to the net thermal photon production rate than $\pi\rho\rightarrow \pi\gamma$, $\pi\pi\rightarrow \rho\gamma$ or $\rho\rightarrow\pi\pi\gamma$. They provide significant contribution to the rate for photon energies as high as 1.5--2.0 GeV. For higher energies they are less important.Comment: 10 pages + 7 figures uuencoded in separate file, MSUCL-92

Projecting the Medium-Term: Outcomes and Errors for GDP Growth

The focus of this paper is the evaluation of a very popular method for potential output estimation and medium-term forecasting - the production function approach - in terms of predictive performance. For this purpose, a forecast evaluation for the three to five years ahead predictions of GDP growth for the individual G7 countries is conducted. To carry out the forecast performance check a particular testing framework is derived that allows the computation of robust test statistics given the specific nature of the generated out-of sample forecasts. In addition, medium-term GDP projections from national and international institutions are examined and it is assessed whether these projections convey a reliable view about future economic developments and whether there is scope for improving their predictive content