Alternative strategies for aggregating prices in the CPI

Consumer price indexes ; Prices

Quality Improvement in Health Care: A Framework for Price and Output Measurement

The durability of health care treatment, the substantial technical change in health care treatment, and the prevalence of third-party payment interact to create substantial difficulty in measuring the price and output of health care. This paper provides a framework for analyzing the demand for health care taking into account these difficulties. It then suggests how this framework might be used to improve measurement of health care prices and output.

Generating Non-Standard Multivariate Distributions with an Application to Mismeasurement in the CPI

This paper shows how to generate the joint distribution of correlated random variables with specified marginal distributions. For cases where the marginal distributions are either normal or lognormal, it shows how to calculate analytically the correlation of the underlying normal distributions to induce the desired correlation between the variables. It also provides a method for calculating the joint distribution in the case of arbitrary marginal distributions. The paper applies the technique to calculating the distribution of the overall bias in the consumer price index. The technique should also be applicable to estimation by simulated moments or simulated likelihoods and to Monte Carlo analysis.

Alternative Strategies for Aggregating Prices in the CPI

The Consumer Price Index does not take into account the fact that consumers alter the composition of their purchases in response to changes in relative prices. This substitution effect will cause the CPI to grow faster than the cost of living. This paper presents new estimates showing that this bias in the CPI averaged 0.3 percentage points per year between December 1986 and December 1995. This bias could be eliminated by using a superlative index to aggregate prices across the item-area strata of the CPI. The paper discusses the practical difficulties in implementing such a calculation and suggests a method for overcoming them. In particular, it shows how to construct an accurate approximation to a superlative price index that can be published with the same timeliness as the CPI.

Mismeasurement in the Consumer Price Index: An Evaluation

A number of analysts have claimed recently that the consumer price index overstates the annual increase in the cost of living. This paper develops a framework for studying measurement problems in the consumer price index and systematically analyzes the available evidence concerning the magnitude of these problems. It concludes that the CPI overstates increases in the cost of living. The evidence suggests that the bias is centered on 1.0 percentage point per year. The extent of this bias is not known exactly. To take into account this uncertainty, the estimated bias is presented in terms of a probability distribution rather than a point estimate or range. We estimate that there is a 10 percent chance that the bias is less than 0.6 percentage point and a 10 percent chance that it is greater than 1.5 percentage points per year. CPI procedures overstate the rate of inflation for medical procedures that are subject to technological improvement. To illustrate this point and to show how better to measure medical care prices, the paper presents a prototypical price index for cataract surgery. This price index grows much more slowly than a price index for cataract surgery constructed using the methodology of the CPI. The paper discusses implications of CPI mismeasurement for monetary and fiscal policy as well as for other official statistics. It also offers some suggestions for improving the CPI.

Biological activity of alginate and its effect on pancreatic lipase inhibition as a potential treatment for obesity

Alginates are classed as a dietary fibre and have been shown to inhibit digestive enzymes in vitro, and therefore could be used as an obesity treatment. The current study aims to assess whether alginate in a bread vehicle maintains its inhibition properties despite cooking and digestion, and may therefore be used as a potential treatment for obesity. After 180 min in a model gut that replicates digestion in the mouth, stomach and small intestines alginate bread (AB), control bread (CB), CB with Manucol® DM alginate, free DM alginate and model gut solution were collected. DM, LFR 5/60 and SF200 were heated at 37 °C and 200 °C, with DM also heated at 50, 100 and 150 °C. Samples from the model gut and heated alginate were assessed for molecular size and inhibition properties using viscosity, gel filtration and a lipase turbidity assay. AB does not significantly increase viscosity in the model gut. Viscosity of alginate reduces beyond 100 °C, although alginate retains its inhibition properties up to 150 °C. Cooking into the bread does not reduce the molecular size of the alginate or affect its inhibition properties. These data demonstrate the robustness of alginates lipase inhibition despite the cooking process and digestion. Therefore adding alginate to a bread vehicle may have the potential in the treatment for obesity

Acceptability of alginate enriched bread and its effect on fat digestion in humans

Lifestyle interventions and physical activity remain the cornerstone of obesity management, as pharmacological therapies (orlistat) are associated with gastrointestinal (GI) side effects. Combining orlistat with fibers can reduce side effects, improving compliance. Therefore, a fiber that inhibits lipase without side effects could help treat obesity. The aims of the present work were to assess whether alginate enriched bread could inhibit fat digestion, and assess the acceptability of alginate bread and its effect on GI wellbeing. A double-blind, randomised, controlled cross-over pilot study (NCT03350958) assessed the impact of an alginate bread meal on; lipid content in ileal effluent and circulating triacylglycerol levels. This was compared against the same meal with non-enriched (control) bread. GI wellbeing and acceptability of alginate bread was compared to control bread through daily wellbeing questionnaires and food diaries (NCT03477981). Control bread followed by alginate bread were consumed for two weeks respectively. Consumption of alginate bread reduced circulating triacylglycerol compared to control (2% reduction in AUC) and significantly increased lipid content in ileal effluent (3.8 g ± 1.6 after 210 min). There were no significant changes to GI wellbeing when comparing alginate bread to control bread. A significant increase in the feeling of fullness occurred with alginate bread compared to baseline and the first week of control bread consumption. This study showed that sustained consumption of alginate enriched bread does not alter GI wellbeing and can decrease lipolysis, increasing lipid leaving the small intestine. Further studies are required to demonstrate that reduced fat digestion through the action of alginate can reduce fat mass or body weight

Contrasting watershed-scale trends in runoff and sediment yield complicate rangeland water resources planning

Rangelands cover a large portion of the earth's land surface and are undergoing dramatic landscape changes. At the same time, these ecosystems face increasing expectations to meet growing water supply needs. To address major gaps in our understanding of rangeland hydrologic function, we investigated historical watershed-scale runoff and sediment yield in a dynamic landscape in central Texas, USA. We quantified the relationship between precipitation and runoff and analyzed reservoir sediment cores dated using cesium-137 and lead-210 radioisotopes. Local rainfall and streamflow showed no directional trend over a period of 85 years, resulting in a rainfall–runoff ratio that has been resilient to watershed changes. Reservoir sedimentation rates generally were higher before 1963, but have been much lower and very stable since that time. Our findings suggest that (1) rangeland water yields may be stable over long periods despite dramatic landscape changes while (2) these same landscape changes influence sediment yields that impact downstream reservoir storage. Relying on rangelands to meet water needs demands an understanding of how these dynamic landscapes function and a quantification of the physical processes at work