Investigating Philadelphia's Uncertified Childcare Providers

Reinvestment Fund's ChildCare Map provides information about the location, size, and quality of early childcare centers operating in Philadelphia. When ChildCare Map launched in 2014 researchers identified a large number of "uncertified providers"--childcare centers operating in Philadelphia, but not listed in the state's OCDEL database. Uncertified providers operate outside of the state's official records, and therefore very little information exists about their size, services, or quality

A Guide to Target Zones

This paper identifies key issues surrounding the advisability and practicality of adopting "target zones" for the exchange rates of major currencies. Pour fundamental questions concerning the definition of and the rationale for target zones are addressed: first, what is generally meant by a "target zone" approach to exchange rate management and how can "hard" and "soft" versions of this approach be defined; second, what are the perceived deficiencies in the existing exchange rate system of managed floating which motivate the call for the adoption of target zones; third, how might target zones remedy these deficiencies; and fourth, what factors are behind much of the skepticism over and opposition to target zones? In addition, the paper deals with a series of operational questions of a more technical nature that weigh heavily on the practicality of implementing a target zone approach. The issues discussed include the following: how would the target zones be calculated; what currencies would be included in the system of target zones; how wide should the target zones be and how frequently should they be revised; and what policy instruments would be employed to keep actual exchange rates within the target zones, and with what consequences for other policy objectives? The purpose of the paper is not to make the case either for or against the adoption of target zones. Rather, the intention is to raise and discuss factors that should be considered in any serious discussion of the topic.

The International Monetary System: Developments and Prospects

This paper addresses several fundamental issues raised by recent developments in the world economy and considers their implications for the design and functioning of the international monetary system. We do not make any proposals. The four issues examined in the paper are: (1) Can the exchange rate regime do much to discipline fiscal policy?; (2) What are the extent and costs of reduced monetary independence under greater fixity of exchange rates?; (3) How can the equilibrium exchange rate best be determined?; (4) Does a well functioning international monetary system require a clearly defined set of rules, an acknowledged leader, and an explicit anchor?

International Coordination of Economic Policies: Scope, Methods, and Effects

This paper discusses the scope, methods, the effects of international coordination of economic policies. In addressing the scope for and of coordination, the analysis covers the rationale for coordination, barriers to coordination, the range and specificity of policies to be coordinated, the frequency of coordination, and the size of the coordinating group. Turning to the methods of coordination, the emphasis is on the broad issues of rules versus discretion, single-indicator versus multi-indicator approaches, and hegemonic versus more symmetric systems. In an attempt to shed some light on the effects of alternative rule- based proposals for coordination, we present some simulations of a global macroeconomic model (MULTIMQD) developed in the International Monetary Fund. The simulations considered range from 'smoothing rules for monetary and fiscal policy that imply only minimal international coordination, to more activist "target-zone" proposals that place greater restrictions on national authorities in the conduct of monetary and/or fiscal policies. The simulation results are compared to the actual evolution of the world economy over the 1974-87 period. Our findings suggest that simple mechanistic rule-based proposals are unlikely to lead to improved performance.

Do More Expensive Wines Taste Better? Evidence from a Large Sample of Blind Tastings

Individuals who are unaware of the price do not derive more enjoyment from more expensive wine. In a sample of more than 6,000 blind tastings, we find that the correlation between price and overall rating is small and negative, suggesting that individuals on average enjoy more expensive wines slightly less. For individuals with wine training, however, we find indications of a positive, or at any rate non-negative, correlation. Our results are robust to the inclusion of individual fixed effects, and are not driven by outliers: when omitting the top and bottom deciles of the price distribution, our qualitative results are strengthened, and the statistical significance is improved even further. Our results indicate that both the prices of wines and wine recommendations by experts may be poor guides for non-expert wine consumers.Wine; price/quality relation; expertise

DO MORE EXPENSIVE WINES TASTE BETTER? EVIDENCE FROM A LARGE SAMPLE OF BLIND TASTINGS

Individuals who are unaware of the price do not derive more enjoyment from more expensive wine. In a sample of more than 6,000 blind tastings, we find that the correlation between price and overall rating is small and negative, suggesting that individuals on average enjoy more expensive wines slightly less. For individuals with wine training, however, we find indications of a positive relationship between price and enjoyment. Our results are robust to the inclusion of individual fixed effects, and are not driven by outliers: when omitting the top and bottom deciles of the price distribution, our qualitative results are strengthened, and the statistical significance is improved further. Our results indicate that both the prices of wines and wine recommendations by experts may be poor guides for non-expert wine consumers.wine quality, wire tasting, wine prices, Demand and Price Analysis,

Development of 3D Compression Molded Composite Primary Structure

The work accomplished by the Black Gold team improved upon the carbon fiber compression molding research and information available on the Cal Poly San Luis Obispo campus. The team used the rear suspension rocker arm off a Ventana Alpino mountain bike as a design goal for this project. This research and body of work includes the methods used to design a compression molded part for complex part loading and shape. This extends to the process of choosing an appropriate layup process, in addition to benefits and drawbacks of the use of chopped fibers in compression molding. The research includes the process and information required to build aluminum molds for compression molded parts of complex shape; manufacturing techniques, and suggestions for the use of compression molding carbon fiber. Finally, data is presented which compares the final compression molding results under ultimate and relative stiffness testing to a comparable part made from aluminum. Ultimately, the team found that compression molding proved to be a potential manufacturing alternative. The rocker arms produced by the team were able to withstand a load of up to 800lbs; meeting the teams initial design criteria before experiencing localized fractures. With future iteration, and more focus on design for loading, the process could yield parts which could carry much higher loads. In addition, the use of chopped fiber around the bearings regions was a success, ultimately showing that a combination of chopped and cloth fiber was a useful load carrying combination. Further research in these processes would definitively improve upon the results obtained by the team, and as information regarding compression molding increases the team expects its use to become more popular

Probing Quark Fragmentation Functions for Spin-1/2 Baryon Production in Unpolarized e+e−e^+e^- Annihilation

We study the measurement of the quark fragmentation functions for spin-1/2 baryon production ($\Lambda$ and $\bar \Lambda$, in particular) in unpolarized $e^+e^-$ annihilation. The spin-dependent fragmentation functions $\hat g_1(z)$ and $\hat h_1(z)$ can be probed in the process as a result of quark-antiquark spin correlation and the weak decay of the baryons. The relevant cross section is expressed as a product of the two-jet cross-section, the fragmentation functions, and the differential width of the hyperon decay.Comment: 17 pages, ReVTeX with (1 figure available from authors), MIT-CTP: #236

Physical Models of Noncovalent Interactions Involving Aromatic Rings

Noncovalent interactions involving π-systems play a vital role throughout chemical and biological processes. These π-interactions can be found in organic photovoltaics and electronics as well as govern many protein and DNA interactions. A fundamental and physically meaningful model of these interactions is necessary for the efficient exploitation of these materials and rational drug design. First, the role of aromaticity in π-stacking, cation/π, and anion/π interactions is investigated. Aromaticity weakly hinders π-stacking and greatly hinders anion/π interactions, while greatly enhancing cation/π interactions. Nonaromatics, therefore, present themselves as a new target in design for π-stacking and anion/π interactions. The well-established local direct interaction model for π-stacking that substituent effects are due solely to local electrostatic changes has also been expanded herein. First, we show that the local direct model for substituent effects in π-stacking also applies to polar XH/π interactions. The nonpolar XH/π interactions vary little with substituent, depending only on changes in dispersion. The energetic changes of both sets of XH/π interactions follow well-known substituent constants. Next, the local direct interaction model is expanded to the use of electric fields to reconcile unusual similarity in the substituent effects between benzene, triazine, and borazine. Substituent effects for different rings are similar as long as the electric fields of those rings are similar in the location of the substituent. In fact, the substituent effect scales proportionally to the relative strength of those fields. Lastly, in an analysis on anion/π complexes with a variety of azines and benzene, it is shown that changes induced through the substitution of a carbon-hydrogen bond with nitrogen are almost exclusively from the nuclear charge differences. This reconciles well with the local direct interaction model