Price, Tobacco Control Policies and Smoking Among Young Adults

The effects of cigarette prices and tobacco control policies (including restrictions on smoking in public places and limits on the availability of tobacco products to youths) on cigarette smoking among youths and young adults are estimated using data from a nationally representative survey of students in U.S. colleges and universities. Smoking participation rates, the quantity of cigarettes smoked by smokers, and level of smoking equations are estimated using appropriate econometric methods. The estimates indicate that college students are quite sensitive to the price of cigarettes, with an average estimated price elasticity of smoking participation of -0.66 and an overall average estimated price elasticity of cigarette smoking of -1.43. In addition, relatively stringent restrictions on smoking in public places are found to reduce smoking participation rates among college students, while the quantity of cigarettes consumed by smokers is lowered by any restrictions on public smoking. Finally, limits on the availability of tobacco products to underage youths have no impact on college students, almost all of whom can legally purchase these products.

The Impact of Price, Availability, and Alcohol Control Policies on Binge Drinking in College

The effects of beer prices, alcohol availability, and policies related to driving under the influence of alcohol on drinking and binge drinking among youths and young adults are estimated using data from a nationally representative survey of students in U.S. colleges and universities. Drinking participation, participation in binge drinking and level of drinking equations are estimated using appropriate econometric methods. The estimates indicate that the drinking practices of college students are sensitive to the price of beer, with an average estimated price elasticity of drinking participation of -0.066 and an average estimated price elasticity of binge drinking of -0.145. However, when dividing the sample by gender, one finds that the effects of prices on drinking are limited to young women. In addition, a significant negative relationship is found for the strength of policies related to drinking and driving among youths and young adults and drinking by college students. However, the results indicate that many elements of campus life, (including participation in a fraternity or sorority, living on campus, and the ready availability of alcoholic beverages) are among the most important determinants of drinking and binge drinking among college students.

Are There Differential Effects of Price and Policy on College Students' Drinking Intensity?

This paper investigates whether college students' response to alcohol price and policies differ according to their drinking intensity. Individual level data on drinking behavior, price paid per drink, and college alcohol policies come from the student and administrator components of the 1997 and 1999 waves of the Harvard School of Public Health (HSPH) College Alcohol Study (CAS). Students drinking behavior is classified on the basis of the number of drinks they typically consume on a drinking occasion, and the number of times they have been drunk during the 30 days prior to survey. A generalized ordered logit model is used to determine whether key variables impact differentially the odds of drinking and the odds of heavy drinking. We find that students who faced a higher money price for alcohol are less likely to make the transition from abstainer to moderate drinker and moderate drinker to heavy drinker, and this effect is equal across thresholds. Campus bans on the use of alcohol are a greater deterrent to moving from abstainer to moderate drinker than moderate drinker to heavy drinker.

Alcohol and Marijuana Use Among College Students: Economic Complements or Substitutes?

College campuses have been cracking down on underage and binge drinking in light of recent highly publicized student deaths. Although there is evidence showing that stricter college alcohol policies have been effective at discouraging both drinking in general and frequent binge drinking on college campuses, recent evidence from the Harvard School Of Public Health College Alcohol Study (CAS) shows that marijuana use among college students rose 22 percent between 1993 and 1999. Are current policies aimed at reducing alcohol consumption inadvertently encouraging marijuana use? This paper begins to address this question by investigating the relationship between the demands for alcohol and marijuana for college students using data from the 1993, 1997 and 1999 CAS. We find that alcohol and marijuana are economic complements and that policies that increase the full price of alcohol decrease participation in marijuana use.

Alcohol policy enforcement and changes in student drinking rates in a statewide public college system: a follow-up study

<p>Abstract</p> <p>Background</p> <p>Heavy alcohol use among U.S. college students is a major contributor to young adult morbidity and mortality. The aim of this study was to examine whether college alcohol policy enforcement levels predict changes in student drinking and related behaviors in a state system of public colleges and universities, following a system-wide change to a stricter policy.</p> <p>Methods</p> <p>Students and administrators at 11 Massachusetts public colleges/universities completed surveys in 1999 (N of students = 1252), one year after the policy change, and again in 2001 (N = 1074). We calculated policy enforcement scores for each school based on the reports of deans of students, campus security chiefs, and students, and examined the correlations between perceived enforcement levels and the change in student drinking rates over the subsequent two year period, after weighting the 2001 data to adjust for demographic changes in the student body.</p> <p>Results</p> <p>Overall rates of any past-30-days drinking, heavy episodic drinking, and usual heavy drinking among past-30-days drinkers were all lower in 2001 compared to 1999. School-level analyses (N = 11) found deans' baseline reports of stricter enforcement were strongly correlated with subsequent declines in heavy episodic drinking (Pearson's r = -0.73, p = 0.011). Moreover, consistently high enforcement levels across time, as reported by deans, were associated with greater declines in heavy episodic drinking. Such relationships were not found for students' and security chiefs' reports of enforcement. Marijuana use did not rise during this period of decline in heavy drinking.</p> <p>Conclusions</p> <p>Study findings suggest that stronger enforcement of a stricter alcohol policy may be associated with reductions in student heavy drinking rates over time. An aggressive enforcement stance by deans may be an important element of an effective college alcohol policy.</p

Annealing a Follow-up Program: Improvement of the Dark Energy Figure of Merit for Optical Galaxy Cluster Surveys

The precision of cosmological parameters derived from galaxy cluster surveys is limited by uncertainty in relating observable signals to cluster mass. We demonstrate that a small mass-calibration follow-up program can significantly reduce this uncertainty and improve parameter constraints, particularly when the follow-up targets are judiciously chosen. To this end, we apply a simulated annealing algorithm to maximize the dark energy information at fixed observational cost, and find that optimal follow-up strategies can reduce the observational cost required to achieve a specified precision by up to an order of magnitude. Considering clusters selected from optical imaging in the Dark Energy Survey, we find that approximately 200 low-redshift X-ray clusters or massive Sunyaev-Zel'dovich clusters can improve the dark energy figure of merit by 50%, provided that the follow-up mass measurements involve no systematic error. In practice, the actual improvement depends on (1) the uncertainty in the systematic error in follow-up mass measurements, which needs to be controlled at the 5% level to avoid severe degradation of the results; and (2) the scatter in the optical richness-mass distribution, which needs to be made as tight as possible to improve the efficacy of follow-up observations.Comment: 12 pages, 7 figures, replaced to match published versio

Weak lensing mass reconstructions of the ESO Distant Cluster Survey

We present weak lensing mass reconstructions for the 20 high-redshift clusters i n the ESO Distant Cluster Survey. The weak lensing analysis was performed on deep, 3-color optical images taken with VLT/FORS2, using a composite galaxy catalog with separate shape estimators measured in each passband. We find that the EDisCS sample is composed primarily of clusters that are less massive than t hose in current X-ray selected samples at similar redshifts, but that all of the fields are likely to contain massive clusters rather than superpositions of low mass groups. We find that 7 of the 20 fields have additional massive structures which are not associated with the clusters and which can affect the weak lensing mass determination. We compare the mass measurements of the remaining 13 clusters with luminosity measurements from cluster galaxies selected using photometric redshifts and find evidence of a dependence of the cluster mass-to-light ratio with redshift. Finally we determine the noise level in the shear measurements for the fields as a function of exposure time and seeing and demonstrate that future ground-based surveys which plan to perform deep optical imaging for use in weak lensing measurements must achieve point-spread functions smaller than a median of 0.6" FWHM.Comment: 35 pages, 24 figures, accepted to A&A, a version with better figure resolution can be found at http://www.mpa-garching.mpg.de/ediscs/papers.htm

Mapping the Dark Matter From UV Light at High Redshift: An Empirical Approach to Understand Galaxy Statistics

We present a simple formalism to interpret two galaxy statistics, the UV luminosity function and two-point correlation functions for star-forming galaxies at z~4, 5, 6 in the context of LCDM cosmology. Both statistics are the result of how star formation takes place in DM halos, and thus are used to constrain how UV light depends on halo properties such as mass. The two measures were taken from the GOODS data, thus ideal for joint analysis. The two physical quantities we explore are the SF duty cycle, and the range of L_UV that a halo of mass M can have (mean and variance). The former addresses the typical duration of SF activity in halos while the latter addresses the averaged SF history and regularity of gas inflow into these systems. We explore various physical models consistent with data, and find the following: 1) the typical duration of SF observed in the data is <0.4 Gyr (1 sig), 2) the inferred scaling law between L_UV and halo mass M from the observed slope of the LFs is roughly linear at all redshifts, and 3) L_UV for a fixed halo mass decreases with time, implying that the SF efficiency (after dust extinction) is higher at earlier times. We explore several physical scenarios relating star formation to halo mass, but find that these scenarios are indistinguishable due to the limited range of halo mass probed by our data. In order to discriminate between different scenarios, we discuss constraining the bright-faint galaxy cross-correlation functions and luminosity-dependence of galaxy bias. (Abridged)Comment: 24 pages, 16 figures: matches published version -- Astrophysical Journal 695 (2009) 368-39

Cosmological Constraints from Galaxy Clustering and the Mass-to-Number Ratio of Galaxy Clusters

We place constraints on the average density (Omega_m) and clustering amplitude (sigma_8) of matter using a combination of two measurements from the Sloan Digital Sky Survey: the galaxy two-point correlation function, w_p, and the mass-to-galaxy-number ratio within galaxy clusters, M/N, analogous to cluster M/L ratios. Our w_p measurements are obtained from DR7 while the sample of clusters is the maxBCG sample, with cluster masses derived from weak gravitational lensing. We construct non-linear galaxy bias models using the Halo Occupation Distribution (HOD) to fit both w_p and M/N for different cosmological parameters. HOD models that match the same two-point clustering predict different numbers of galaxies in massive halos when Omega_m or sigma_8 is varied, thereby breaking the degeneracy between cosmology and bias. We demonstrate that this technique yields constraints that are consistent and competitive with current results from cluster abundance studies, even though this technique does not use abundance information. Using w_p and M/N alone, we find Omega_m^0.5*sigma_8=0.465+/-0.026, with individual constraints of Omega_m=0.29+/-0.03 and sigma_8=0.85+/-0.06. Combined with current CMB data, these constraints are Omega_m=0.290+/-0.016 and sigma_8=0.826+/-0.020. All errors are 1-sigma. The systematic uncertainties that the M/N technique are most sensitive to are the amplitude of the bias function of dark matter halos and the possibility of redshift evolution between the SDSS Main sample and the maxBCG sample. Our derived constraints are insensitive to the current level of uncertainties in the halo mass function and in the mass-richness relation of clusters and its scatter, making the M/N technique complementary to cluster abundances as a method for constraining cosmology with future galaxy surveys.Comment: 23 pages, submitted to Ap

The Dynamical State and Mass-Concentration Relation of Galaxy Clusters

We use the Millennium Simulation series to study how the dynamical state of dark matter halos affects the relation between mass and concentration. We find that a large fraction of massive systems are identified when they are substantially out of equilibrium and in a particular phase of their dynamical evolution: the more massive the halo, the more likely it is found at a transient stage of high concentration. This state reflects the recent assembly of massive halos and corresponds to the first pericentric passage of recently-accreted material when, before virialization, the kinetic and potential energies reach maximum and minimum values, respectively. This result explains the puzzling upturn in the mass-concentration relation reported in recent work for massive halos; indeed, the upturn disappears when only dynamically-relaxed systems are considered in the analysis. Our results warn against applying simple equilibrium models to describe the structure of rare, massive galaxy clusters and urges caution when extrapolating scaling laws calibrated on lower-mass systems, where such deviations from equilibrium are less common. The evolving dynamical state of galaxy clusters ought to be carefully taken into account if cluster studies are to provide precise cosmological constraints.Comment: 8 Pages. Minor changes to match published versio