Falling Gasoline Prices Lead to Lowest Inflation Since 2008

Overall price change was modest in 2014, with the U.S. All Items Consumer Price Index posting its smallest increase since 2008. This was primarily the result of gasoline prices, which fell sharply over the latter part of the year. However, shelter and food price indexes accelerated in 2014. In this Beyond the Numbers article, we will look at price trends for major CPI components in 2014

Measures of Gasoline Price Change

[Excerpt] No prices are more visible to the public than gasoline prices. Even for people who don’t have to fill up a tank on a regular basis, gasoline prices are likely to be in their view, posted every day. In addition, no prices have more of an impact on short-run movements in the Consumer Price Index (CPI). Gasoline prices are so much more volatile than other CPI components that, even though gasoline makes up less than 6 percent of the CPI, it is often the main source of monthly price movements in the all items index. Moreover, because they are so visible and gasoline is purchased so frequently, gasoline prices have a major impact on the perception of prices. Constantly seeing prices at the pump creep ever higher will often create a perception of broader inflation—and, of course, higher gasoline prices are likely to eventually have an impact on other prices as transportation costs increase. So, it is particularly important that gasoline price changes be measured accurately and reliably. Fortunately, gasoline is one of the few consumer goods for which there are many sources of price data. In fact, the ease of price collection makes it feasible for other government agencies and even private sources to create reliable measures. On the government side, the Energy Information Administration (EIA) publishes extensive gasoline price data. Among private sources are the American Automobile Association, the Oil Price Information Service, and the Lundberg Survey. Furthermore, gasoline is one of the few nonfood items for which the Bureau of Labor Statistics (BLS) publishes an average price series as well as an index; the fact that gasoline is a relatively homogenous product makes meaningful average price data possible. This article examines three measures of gasoline prices: the BLS Consumer Price Index for All Urban Consumers (CPI-U) U.S. city average for all types of gasoline, the BLS CPI average price series for all types of gasoline, and the EIA Weekly Retail Gasoline and Diesel Prices for all grades of gasoline. The purpose of the article is to identify how these measures have behaved over the 10-year period from December 2002 to December 2012

Consumer Price Index Data Quality: How Accurate is the U.S. CPI?

The Consumer Price Index (CPI) is an estimate of the average change in prices over time paid by urban consumers for a market basket of consumer goods and n the United States. The CPI is used extensively in many different ways, including three major uses: to adjust historical data, to escalate federal payments and tax brackets, and to adjust rents and wages. It directly affects the lives of Americans, so it must be as accurate as possible. But how accurate is it? If, for example, the CPI measures annual inflation as 2.3 percent, how confident can we be in that estimate? This issue of BEYOND THE NUMBERS looks at some different ways the U.S. Bureau of Labor Statistics (BLS) has responded to questions about the accuracy and precision of the CPI. The first section examines the sampling error of the CPI, and the second section discusses possible sources of bias in the index

Analysis of pathogenic bacteria using exogenous volatile organic compound metabolites and optical sensor detection

A novel, low-cost and simple method for the detection of pathogenic bacteria is proposed. The approach is based on the generation of an exogenous volatile organic compound (VOC) produced by the addition of an enzyme substrate to the bacterial sample. The generated VOC is then trapped in agarose gel allowing colour development to take place; visual detection is then possible by both the naked eye and by colorimetric analysis. Agarose gel has been evaluated as both a suitable VOC trapping matrix and host for the colour-generating reagents. This proof of concept method allowed for the discrimination between β-glucosidase and β-alanyl aminopeptidase producing bacteria. Enterococcus faecium and Klebsiella pneumoniae are both β-glucosidase producers and generated a yellow colour within agarose gels upon enzymatic hydrolysis of 2-nitrophenyl-β-D-glucoside. Pseudomonas aeruginosa is a known β-alanyl aminopeptidase producer and was shown to hydrolyse the trifluoroacetic acid (TFA) salt of 3-amino-N-phenylpropanamide resulting in the development of an orange colour within agarose gels spiked with the sodium salt of 1,2-naphthoquinone-4-sulfonic acid. 3-Amino-N-phenylpropanamide (as its TFA salt) and 2-nitrophenyl-β-D-glucoside concentrations of 20 μg mL−1 (or 72 μmol L−1) and 100 μg mL−1 (or 332 μmol L−1), respectively were the minimum quantities required for colour production following 18 h of incubation. The use of 3-amino-N-phenylpropanamide, TFA salt indicated that synthesised enzyme substrates can be tailor-made to liberate exogenous VOCs for colour generation

More Evidence on the Use of Constructed-Response Questions in Principles of Economics Classes

This study provides evidence that constructed response (CR) questions contribute information about student knowledge and understanding that is not contained in multiple choice questions (MC). We use an extensive data set of individual assessment results from Introductory Macro- and Microeconomics classes at a large, public university. We find that (i) CR scores contain information not contained in MC questions, (ii) this information is correlated with a measure of student knowledge and understanding of course material, and (iii) CR questions are better able to “explain” academic achievement in other courses than additional MC questions. There is some evidence to suggest that this greater explanatory power has to do with the ability of CR questions to measure higher-level learning as characterized by Bloom’s taxonomy (Bloom, 1956). Both (i) the generalisability of our results to other principles of economics classes, and (ii) the practical significance (in terms of students’ grades) of our findings, remain to be determined.Principles of Economics Assessment; Multiple Choice; Constructed Response; Free Response; Essay

Do Constructed-Response and Multiple-Choice Questions Measure the Same Thing?

Our study empirically investigates the relationship between constructed-response (CR) and multiple-choice (MC) questions using a unique data set compiled from several years of university introductory economics classes. We conclude that CR and MC questions do not measure the same thing. Our main contribution is that we show that CR questions contain independent information that is related to student learning. Specifically, we find that the component of CR scores that cannot be explained by MC responses is positively and significantly related to (i) performance on a subsequent exam in the same economics course, and (ii) academic performance in other courses. Further, we present evidence that CR questions provide information that could not be obtained by expanding the set of MC questions. A final contribution of our study is that we demonstrate that empirical approaches that rely on factor analyses or Walstad-Becker (1994)-type regressions are unreliable in the following sense: It is possible for these empirical procedures to lead to the conclusion that CR and MC questions measure the same thing, even when the underlying data contain strong, contrary evidence. JEL Classifications: A22Principles of Economics Assessment; Multiple Choice; Constructed Response; Free Response; Essay

More Evidence on the Use of Constructed-Response Questions in Principles of Economics Classes

This study provides evidence that constructed response (CR) questions contribute information about student knowledge and understanding that is not contained in multiple choice questions (MC). We use an extensive data set of individual assessment results from Introductory Macro- and Microeconomics classes at a large, public university. We find that (i) CR scores contain information not contained in MC questions, (ii) this information is correlated with a measure of student knowledge and understanding of course material, and (iii) CR questions are better able to ‘explain’ academic achievement in other courses than additional MC questions. There is some evidence to suggest that this greater explanatory power has to do with the ability of CR questions to measure higher-level learning as characterised by Bloom’s taxonomy (Bloom, 1956). Both (i) the generalisability of our results to other principles of economics classes, and (ii) the practical significance (in terms of students’ grades) of our findings, remain to be determined.

Structural Change and Competition in Seven U.S. Food Markets

Recent trends in mergers and acquisitions in the U.S. food sector food manufacturers, wholesalers, and retailers raise concerns about market power. In the presence of market power, farmers may receive lower than competitive farm prices, and consumers may pay higher than competitive retail prices. This study presents empirical tests of market power at the national level for seven food categories: beef, pork, poultry, eggs, dairy, fresh fruit, and fresh vegetables. At the national level, our tests provide evidence of competitive conduct in both the sale of final food products and the purchase of farm ingredients.retail food and farm prices, market power, structural change, cointegration, Agribusiness, Industrial Organization,

Staged implementation of an agent based advanced gas-cooled reactor condition monitoring system

This paper introduces iMAPS, the intelligent monitoring assessment panel system used by nuclear electricity generator British Energy in the UK. A multi-agent system design was chosen for this system and the paper describes why this technique was chosen and shows how this will allow the project to meet the short-term goals of the sponsor whilst providing a foundation for a plant-wide analysis system. Experience of building the initial stage of this system is also included, along with observations on the agent-based approach. The system was developed by the Institute for Energy and Environment at the University of Strathclyde and is in use by British Energy Generation