11,854 research outputs found
When Teachers Choose Pension Plans: The Florida Story
Although long ignored by education-policy analysts, the structure of teacher retirement benefits has come under increasing scrutiny in recent years. The vast majority of teachers, like other state and local public employees, are covered by traditional defined-benefit (DB) pension plans. Now rare in the private sector of the United States economy, these plans provide a retired teacher with a guaranteed lifetime benefit, the annual value of which is typically based on his number of years of service and average salary during the final years of his career. A teacher is often required to contribute from her salary to funds set aside to pay for this plan, but the size of her benefit is not tied to the amount of any contributions.Critics of existing teacher pension systems raise two broad sets of concerns. First, they note that the time lag between when the government funds and pays out retirement benefits encourages politicians to contribute too little to their pension systems, effectively borrowing from future taxpayers to fund current spending on government services.The shortfalls facing state and local pension systems covering teachers and other public workers due to persistent underfunding are staggering. Novy-Marx and Rauh13 estimate that achieving full funding of promised pension liabilities nationally over thirty years would require a tax increase of $1,385 per household each year. A more likely outcome is substantial cuts to public services such as education.Second, critics note that the reliance on traditional DB pension plans makes total teacher compensation severely back-loaded, potentially hindering efforts to improve teacher quality. Most of these plans have vesting periods of five or more years and are structured so that employees do not amass substantial benefits until late in their careers -- at which point benefits increase rapidly. These features may make teaching less attractive to individuals who are uncertain of whether they will remain in the profession long enough to benefit or would prefer to receive a higher salary to support present consumption. Recent evidence confirms that DB pension plans lead some veteran teachers to continue teaching solely for the sake of increasing pension wealth, while encouraging others to retire prematurely so as not to sacrifice years of benefit payments.The back-loading of benefits also imposes heavy costs on career-switchers and geographically mobile teachers, who typically stand to receive benefits worth far less than the pension contributions made on their behalf. The most prominent alternative to a traditional DB pension plan is the defined contribution (DC) model. Under DC plans, an employee builds up an individual retirement account through her or her employer's regular contributions throughout her career and exercises some control over how the account is invested. Because the value of that account is tied directly to these contributions (and the performance of investments), DC plans, by definition, cannot be underfunded. Rapidvesting, portability, and the smooth accrual of benefits over time eliminate the problematic end-of-career incentives created by existing DB plans and could make teaching more attractive to young workers, possible career-switchers, or those likely to be geographically mobile.Finally, because benefits take the form of a personal account that can be converted into a lifetime annuity, the employee gains control over the timing and structure of her retirement benefit. An important potential drawback of the DC model is that employees, rather than taxpayers, bear the consequences if disappointing investment returns or poor withdrawal decisions yield inadequate retirement savings. Unions representing teachers and other public employees have vigorously opposed proposals to convert public pension plans to the DC model, largely on these grounds. Proponents of DB pensions cite survey data suggesting that public employees strongly prefer the DB model and contend that "when given the choice between a primary DB or DC plan, public employees overwhelmingly choose the DB pension plan."Yet there is reason to believe that many current and potential teachers could find well-designed DC plans as or more attractive than traditional DB plans. As noted above, DB plans typically provide minimal benefits to those who do not remain in the profession (and in the same state retirement system) for many years. They may therefore be unappealing to a younger generation of workers prone to exploring multiple career paths before settling on one. Other teachers may simply prefer to exercise greater control over their retirement savings, either due to confidence in their investment abilities or to doubts as to whether public pension funds will be able to deliver on their promises. Consistent with this logic, a survey of Washington State teachers found that a plurality of teachers would prefer to invest additional retirement savings in a DC plan rather than in a DB plan. The extent to which preferences expressed on surveys correspond to the actual behavior of teachers when given the option remains unclear.In this paper, we examine teacher preferences as revealed by their decisions when empowered to choose between alternative pension-plan structures. Since 2002, public school teachers (and most other state and local employees) in Florida have been permitted to choose between a traditional DB retirement plan and a new DC plan. During the time period of our study, school districts were required to contribute 9 percent of the salary of teachers taking the DC option to personalinvestment accounts in their names. Neither DB nor DC choosers were required to contribute from their own salaries to the retirement system, meaning that teachers' plan choice did not alter their take-home pay. The benefits of teachers choosing the DC plan vested after just one year, as compared with six under the DB plan
Do More Effective Teachers Earn More Outside of the Classroom?
We examine earnings records for 90,000 classroom teachers employed by Florida public schools between the 2001–02 and 2006–07 school years, roughly 20,000 of whom left teaching during that time. Among grade 4–8 teachers leaving for other industries, a 1 standard deviation increase in estimated value-added to student achievement is associated with 6–9 percent higher earnings outside of teaching. The relationship between effectiveness and earnings is stronger in other industries than it is for the same teachers while in the classroom, suggesting that existing compensation systems do not account for the higher opportunity wages of effective teachers.
Short-term Response of Holcus lanatus L. (Common Velvetgrass) to Chemical and Manual Control at Yosemite National Park, USA
One of the highest priority invasive species at both Yosemite and Sequoia and Kings Canyon national parks is Holcus lanatus L. (common velvetgrass), a perennial bunchgrass that invades mid-elevation montane meadows. Despite velvetgrass being a high priority species, there is little information available on control techniques. The goal of this project was to evaluate the short-term response of a single application of common chemical and manual velvetgrass control techniques. The study was conducted at three montane sites in Yosemite National Park. Glyphosate spotspray treatments were applied at 0.5, 1.0, 1.5, and 2.0% concentrations, and compared with hand pulling to evaluate effects on cover of common velvetgrass, cover of other plant species, and community species richness. Posttreatment year 1 cover of common velvetgrass was 12.1% 6 1.6 in control plots, 6.3% 6 1.5 averaged over the four chemical treatments (all chemical treatments performed similarly), and 13.6% 6 1.7 for handpulled plots. This represents an approximately 50% reduction in common velvetgrass cover in chemically- treated plots recoded posttreatment year 1 and no statistically significant reduction in hand pulled plots compared with controls. However, there was no treatment effect in posttreatment year 2, and all herbicide application rates performed similarly. In addition, there were no significant treatment effects on nontarget species or species richness. These results suggest that for this level of infestation and habitat type, (1) one year of hand pulling is not an effective control method and (2) glyphosate provides some level of control in the short-term without impact to nontarget plant species, but the effect is temporary as a single year of glyphosate treatment is ineffective over a twoyear period
Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope
The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of
the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object
with relatively low astrophysical backgrounds, it is a natural target for dark
matter indirect detection searches. In this work, we use six years of Pass 8
data from the Fermi Large Area Telescope to search for gamma-ray signals of
dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray
backgrounds, and a combination of N-body simulations and direct measurements of
rotation curves to estimate the SMC DM density profile, we found that the SMC
was well described by standard astrophysical sources, and no signal from dark
matter annihilation was detected. We set conservative upper limits on the dark
matter annihilation cross section. These constraints are in agreement with
stronger constraints set by searches in the Large Magellanic Cloud and approach
the canonical thermal relic cross section at dark matter masses lower than 10
GeV in the and channels.Comment: 17 pages, 11 figures. Accepted by PR
Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope
At a distance of 50 kpc and with a dark matter mass of
M, the Large Magellanic Cloud (LMC) is a natural target for indirect
dark matter searches. We use five years of data from the Fermi Large Area
Telescope (LAT) and updated models of the gamma-ray emission from standard
astrophysical components to search for a dark matter annihilation signal from
the LMC. We perform a rotation curve analysis to determine the dark matter
distribution, setting a robust minimum on the amount of dark matter in the LMC,
which we use to set conservative bounds on the annihilation cross section. The
LMC emission is generally very well described by the standard astrophysical
sources, with at most a excess identified near the kinematic center
of the LMC once systematic uncertainties are taken into account. We place
competitive bounds on the dark matter annihilation cross section as a function
of dark matter particle mass and annihilation channel.Comment: 33 pages, 22 figures Version 2: minor corrections and clarifications
after journal peer review proces
The Effects of Participation in Alternative Break: An Alumni Sample Study
Alternative break experiences occur when college or university students choose freely to eschew typical break activities in order to engage in service with a group of peers under the guidance of peer-leaders in a community removed from their own. While researchers have identified some immediate benefits of participation in alternative break experience, less is known about their long-term impacts. This article examines the results of a study in which 147 college graduates were asked to reflect on their alternative break experiences. Respondents reported that these experiences had long-term (i.e., post-graduate) effects such as fostering lasting relationships and changing life perspectives
Radion Induced Brane Preheating
When the interbrane separation in compact Randall-Sundrum models is
stabilized via the Goldberger-Wise mechanism, a potential is generated for the
four dimensional field that encodes this geometric information, the so-called
radion. Due to its origin as a part of the full five dimensional metric, the
radion couples directly to particles on both branes. We exhibit the exponential
growth in the number of brane particles due to parametric amplification from
radion oscillations and discuss some of the consequences of this process for
brane cosmology.Comment: 4 pages, uses ReVTeX, 3 postscript figure
1+1 Dimensional Compactifications of String Theory
We argue that stable, maximally symmetric compactifications of string theory
to 1+1 dimensions are in conflict with holography. In particular, the finite
horizon entropies of the Rindler wedge in 1+1 dimensional Minkowski and anti de
Sitter space, and of the de Sitter horizon in any dimension, are inconsistent
with the symmetries of these spaces. The argument parallels one made recently
by the same authors, in which we demonstrated the incompatibility of the
finiteness of the entropy and the symmetries of de Sitter space in any
dimension. If the horizon entropy is either infinite or zero the conflict is
resolved.Comment: 11 pages, 2 figures v2: added discussion of AdS_2 and comment
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