Dismal Science: The Shortcomings of U.S. School Choice Research and How to Address Them

Pressing questions about the merits of market accountability in K-12 education have spawned a large scholarly literature. Unfortunately, much of that literature is of limited relevance, and some of it is misleading. The studies most widely cited in the United States used intense scrutiny of a few small-scale, restriction-laden U.S. programs -- and a handful of larger but still restriction-laden foreign school choice expansions -- to assert general conclusions about the effects of "choice," "competition," and "markets." The most intensely studied programs lack most or all of the key elements of market systems, including profit, price change, market entry, and product differentiation -- factors that are normally central to any discussion of market effects. In essence, researchers have drawn conclusions about apples by studying lemons. To address the need for credible evidence on the effects of genuine education markets, economists should look to simulation models, indirect evidence such as outcomes in similar industries, and school systems abroad that enjoy varying degrees of market accountability

The Merrifield-Simmons conjecture holds for bipartite graphs

Let $G = (V, E)$ be a graph and $\sigma(G)$ the number of independent (vertex) sets in $G$. Then the Merrifield-Simmons conjecture states that the sign of the term $\sigma(G_{-u}) \cdot \sigma(G_{-v}) - \sigma(G) \cdot \sigma(G_{-u-v})$ only depends on the parity of the distance of the vertices $u, v \in V$ in $G$. We prove that the conjecture holds for bipartite graphs by considering a generalization of the term, where vertex subsets instead of vertices are deleted.Comment: 8 page

Buckling Bars and Boxy Bulges

It has been suggested that the peanut-shaped bulges seen in some edge-on disk galaxies are produced when bars in these galaxies buckle. This paper reviews the modelling which seeks to show how bars buckle, and I present a very simple new model which captures the essential physics of this process. I then discuss the problems in establishing observationally the connection between peanut-shaped bulges and bars: confirmation of the link has proved difficult because boxy bulges are only apparent in edge-on galaxies whereas bars are only easily detectable in more face-on systems. Finally, I present a new technique which avoids this difficulty by searching for the distinctive kinematic signature of an edge-on bar; application of this method to spectra of peanut-shaped bulges reveals that they are, indeed, associated with hidden bars.Comment: uuencoded compressed postcript, 9 pages. Invited talk at IAU Colloquium #157: Barred Galaxies. The figures (some of which are rather large) are available over the WWW from our preprint server at http://www.astro.soton.ac.uk/pubs/Publications.htm

Dark Matter on Galactic Scales (or the Lack Thereof)

This paper presents a brief review of the evidence for dark matter in the Universe on the scales of galaxies. In the interests of critically and objectively testing the dark matter paradigm on these scales, this evidence is weighed against that from the only other game in town, modified Newtonian dynamics. The verdict is not as clear cut as one might have hoped.Comment: 10 pages, 5 figures. Invited review talk presented at IDM2004 5th International Workshop on the Identification of Dark Matter, Edinburgh, Scotland, September 200

Does Money Matter? The Impact of State Political Context on the Relationship between Race/Ethnicity and Campaign Finance

Despite increasing campaign-finance legislation aimed at equalizing barriers in political campaigns, a fundraising gap persists across racial/ethnic lines. In the era of modern campaigning, with the expenses of advertising and polling, among others, ample funds are necessary but not accessible to all candidates. This study addresses the relationship between candidate race/ethnicity and campaign fundraising, and the possible moderating effect of three dimensions of the state political context: state legislative professionalism, state Republican party strength, and state culture (South vs. non-South). I evaluate fundraising totals across 15 states for more than 3,000 candidates in the 2006 state legislative elections. Ultimately, the findings suggest that after controlling for other candidate characteristics, as well as for district and state context, there is a negative statistically significant relationship between candidate race/ethnicity and fundraising. In addition, the effect of race/ethnicity is moderated by two features of the state context: legislative professionalization and state culture. This study finds that nonwhite candidates continue to fundraise less than their white counterparts and that state context is important in understanding the race/ethnicity gap in campaign finance

The Kinematics of Galactic Stellar Disks

The disks of galaxies are primarily stellar systems, and fundamentally dynamical entities. Thus, to fully understand galactic disks, we must study their stellar kinematics as well as their morphologies. Observational techniques have now advanced to a point where quite detailed stellar-kinematic information can be extracted from spectral observations. This review presents three illustrative examples of analyses that make use of such information to study the formation and evolution of these systems: the derivation of the pattern speed of the bar in NGC 936; the calculation of the complete velocity ellipsoid of random motions in NGC 488; and the strange phenomenon of counter-rotation seen in NGC 3593.Comment: 11 pages, LaTeX (including 7 figures), uses paspconf.sty and epsf.sty, to be published in Proceedings of the EC Summer School on 'Astrophysical Discs', eds J. A. Sellwood and J. Goodman, ASP Conf. Serie

The pattern speed of the bar in NGC 936

We have used the Tremaine-Weinberg method to measure the angular speed of rotation for the bar in the SB0 galaxy NGC 936. With this technique, the bar's pattern speed, Omega_p, can be derived from the luminosity and stellar-kinematic information in long-slit spectral observations taken parallel to the major axis of the galaxy. The kinematic measurement required is the mean line-of-sight velocity of all stellar light entering the slit. This quantity can only be calculated reliably if any asymmetry in the shape of the broadening function of the spectral lines is also measured, and so we present a method which allows for such asymmetry. The technique also returns a true measure of the RMS uncertainty in the estimate. Application of the analysis to a set of long-slit spectra of NGC 936 returns four separate measures of Omega_p which are mutually consistent. Combining these data produces a best estimate for the bar pattern speed of Omega_p = 60 +/- 14 km/s/kpc (assuming a distance of 16.6 Mpc). This result refines the only previous attempt to make this measurement, which yielded an estimate for Omega_p in NGC 936 of 104 +/- 37 km/s/kpc (Kent 1987). The new measurement places the co-rotation radius just beyond the end of the bar, in agreement with theoretical calculations.Comment: uuencoded compressed postscript file. 6 pages. Accepted for publication in MNRAS