The Impact of After-School Programs: Interpreting the Results of Four Recent Evaluations

Within the last decade, after-school programs have moved from the periphery to the center of the national education policy debate. The demand for after-school care by working parents and a new focus on test-based accountability are the two primary reasons. Reflecting these pressures, federal funding for after-school programs has grown dramatically over the last half-decade. Between 1998 and 2002, federal funding for the 21st Century Community Learning Centers program grew from $40 million to$1 billion. State and local governments have also increased their funding, with California committing itself to a six- fold increase in funding for after-school programs over the next few years.As a wave of evaluation results has recently become available, policymakers are understandably eager to see evidence that these investments are paying off. The purpose of this review is to summarize the results of four recent evaluations, to draw the lessons we have learned so far, and to identify the unanswered questions

Rising Public College Tuition and College Entry: How Well Do Public Subsidies Promote Access to College?

Though economists have spent the past decade analyzing the rising payoff to schooling, we know much less about the responses of youth or the effectiveness of policies aimed at influencing those decisions. States and the federal government currently spend more than $53 billion annually, hoping to promote greater access to college. This paper evaluates the price sensitivity of youth, using several sources of non-experimental variation in costs. The bulk of the evidence points to large enrollment impacts, particularly for low-income students and for those attending two-year colleges. The states have chosen to promote college enrollment by keeping tuition low through across-the-board subsidies rather than using more targeted, means-tested aid. As public enrollments increase, this has become an expensive strategy. Means-tested aid may be better targeted. However, the evidence of enrollment responses to such targeted aid is much weaker. After a federal means-tested grant program was established in 1973, there was no disproportionate increase in enrollment by low-income youth. Given the number of public dollars at stake, the two sets of results should be reconciled.

Is the German apprenticeship system a panacea for the US labour market?

Advocates of apprenticeship programs often argue as if it is simply a matter of historical accident which has hindered such investment by U.S. firms. This paper explores the structure of incentives undergirding the German system of apprenticeship training. First, we describe three characteristics of the German labor market which may lead firms to accept part of the cost of general training, even in the face of worker turnover. In the second part of the paper, we compare labor market outcomes for apprentices in Germany and high school graduates in the United States. Apprentices in Germany occupy a similar station within the German wage structure as held by high school graduates in the V.S. labor market. Finally, we provide evidence that the problem of forming labor market bonds is particularly acute for minority youth --in Germany as well as in the U.S.. We discuss some implications for the vocational training debate in the U.S.

Coherent communication link using diode-pumped lasers

Work toward developing a diffraction limited, single frequency, modulated transmitter suitable for coherent optical communication or direct detection communication is discussed. Diode pumped, monolithic Nd:YAG nonplanar ring oscillators were used as the carrier beam. An external modulation technique which can handle high optical powers, has moderate modulation voltage, and which can reach modulation rates of 1 GHz was invented. Semiconductor laser pumped solid-state lasers which have high output power (0.5 Watt) and which oscillate at a single frequency, in a diffraction limited beam, at the wavelength of 1.06 microns were built. A technique for phase modulating the laser output by 180 degrees with a 40-volt peak to peak driving voltage is demonstrated. This technique can be adapted for amplitude modulation of 100 percent with the same voltage. This technique makes use of a resonant bulk modulator, so it does not have the power handling limitations of guided wave modulators

Improving School Accountability Measures

A growing number of states are using annual school-level test scores as part of their school accountability systems. We highlight an under-appreciated weakness of that approach the imprecision of school-level test score means -- and propose a method for better discerning signal from noise in annual school report cards. For an elementary school of average size in North Carolina, we estimate that 28 percent of the variance in 5th grade reading scores is due to sampling variation and about 10 percent is due to other non-persistent sources. More troubling, we estimate that less than half of the variance in the mean gain in reading performance between 4th and 5th grade is due to persistent differences between schools. We use these estimates of the variance components in an empirical Bayes framework to generate filtered' predictions of school performance, which have much greater predictive value than the mean for a single year. We also identify evidence of within-school heterogeneity in classroom level gains, which suggests the importance of teacher effects.

Estimating Returns to Schooling When Schooling is Misreported

We propose a general method of moments technique to identify measurement error in self-reported and transcript-reported schooling using differences in wages, test scores, and other covariates to discern the relative verity of each measure. We also explore the implications of such reporting errors for both OLS and IV estimates of the returns to schooling. The results cast a new light on two common findings in the extensive literature on the returns to schooling: sheepskin effects' and the recent IV estimates, relying on natural experiments' to identify the payoff to schooling. First, respondents tend to self-report degree attainment much more accurately than they report educational attainment not corresponding with degree attainment. For instance, we estimate that more than 90 percent of those with associate's or bachelor's degrees accurately report degree attainment, while only slightly over half of those with 1 or 2 years of college credits accurately report their educational attainment. As a result, OLS estimates tend to understate returns per year of schooling and overstate degree effects. Second, because the measurement error in educational attainment is non-classical, IV estimates also tend to be biased, although the magnitude of the bias depends upon the nature of the measurement error in the region of educational attainment affected by the instrument.

Roe v. Wade and American Fertility

We consider the effect of abortion legalization on births in the United States. A simple theoretical model demonstrates that the impact of abortion legalization on the birth rate is ambiguous, because both pregnancy and abortion decisions could be affected. We use variation in the timing of legalization across states in the early 1970's to estimate the effect of abortion on birth rates. Our findings indicate that states legalizing abortion experienced a 5% decline in births relative to other states. The decline among teens, women over 35, and nonwhite women was even greater: 13%, 8%, and 12% respectively. Out-of-wedlock births declined by twice as much as births in wedlock. If legalization in some states affected birth rates in neighboring states (through travel to obtain an abortion), comparing births between states will underestimate the actual reduction. Using more distant comparison states increases the estimated impact of abortion legalization on birth rates to about 8%. Applying this estimate to the current level of births, a complete recriminalization of abortion would result in 320,000 additional births per year.

Prototype laser-diode-pumped solid state laser transmitters

Monolithic, diode-pumped Nd:YAG ring lasers can provide diffraction-limited, single-frequency, narrow-linewidth, tunable output which is adequate for use as a local oscillator in a coherent communication system. A laser was built which had a linewidth of about 2 kHz, a power of 5 milliwatts, and which was tunable over a range of 30 MHz in a few microseconds. This laser was phase-locked to a second, similar laser. This demonstrates that the powerful technique of heterodyne detection is possible with a diode-pumped laser used as the local oscillator. Laser diode pumping of monolithic Nd:YAG rings can lead to output powers of hundreds of milliwatts from a single laser. A laser was built with a single-mode output of 310 mW. Several lasers can be chained together to sum their power, while maintaining diffraction-limited, single frequency operation. This technique was demonstrated with two lasers, with a total output of 340 mW, and is expected to be practical for up to about ten lasers. Thus with lasers of 310 mW, output of up to 3 W is possible. The chaining technique, if properly engineered, results in redundancy. The technique of resonant external modulation and doubling is designed to efficiently convert the continuous wave, infrared output of our lasers into low duty-cycle pulsed green output. This technique was verified through both computer modeling and experimentation. Further work would be necessary to develop a deliverable system using this technique