The Monthly Measurement of Core Inflation in Japan

This paper considers the use of trimmed means as monthly indicators of Japanese core inflation. As in Bryan, Cecchetti, and Wiggins (1997) for the United States, and Roger (1997) for New Zealand, we find that trimming the tails of the price change distribution substantially improves high-frequency estimates of Japanese core inflation. These estimators yield efficiency gains of roughly two-thirds over the Japanese CPI. While we find that trimming approximately 35 percent from each tail of the price change distribution produces the most efficient monthly estimator over the full 27-year period, a range of trimmed-mean estimators (between 21 percent and the median price change) provide nearly the same signal. Moreover, we find that these estimators are superior to the standard monthly core inflation estimator in Japan, the CPI less fresh food. At lower frequencies (12-month percent changes and beyond), the differences between the candidate estimators were found to be small, and the trimmed estimators were nearly the same as the CPI less fresh food and energy along many dimensions.

Monitoring core inflation

An analysis of the use of limited-information estimators as measures of core inflation, showing that these estimators, such as the median of the cross-sectional distribution of inflation, have a higher correlation with past money growth and deliver improved forecasts of future inflation relative to the Consumer Price Index.Inflation (Finance)

The seasonality of consumer prices

A reevaluation of the evidence of seasonality in prices, finding that seasonal price movements have become more prominent in the relatively stable inflation environment that has prevailed since 1982, and that the amount of seasonality differs greatly by item, making it difficult to generalize about seasonal price movements.Consumer price indexes ; Seasonal variations (Economics)

Asset Prices in the Measurement of Inflation

The debate over including asset prices in the construction of an inflation statistic has attracted renewed attention in recent years. Virtually all of this (and earlier) work on incorporating asset prices into an aggregate price statistic has been motivated by a presumed, but unidentified transmission mechanism through which asset prices are leading indicators of inflation at the retail level. In this paper, we take an alternative, longer-term perspective on the issue and argue that the exclusion of asset prices introduces an 'excluded goods bias' in the computation of the inflation statistic that is of interest to the monetary authority. We implement this idea using a relatively modern statistical technique, a dynamic factor index. This statistical algorithm allows us to see through the excessively 'noisy' asset price data that have frustrated earlier researchers who have attempted to integrate these prices into an aggregate measure. We find that the failure to include asset prices in the aggregate price statistic has introduced a downward bias in the U.S. Consumer Price Index on the order of magnitude of roughly 1/4 percentage point annually. Of the three broad assets categories considered here -- equities, bonds, and houses -- we find that the failure to include housing prices resulted in the largest potential measurement error. This conclusion is also supported by a cursory look at some cross-country evidence.

Efficient Inflation Estimation

This paper investigates the use of trimmed means as high-frequency estimators of" inflation. The known characteristics of price change distributions, specifically the observation" that they generally exhibit high levels of kurtosis, imply that simple averages of price data are" unlikely to produce efficient estimates of inflation. Trimmed means produce superior estimates" of core inflation,' which we define as a long-run centered moving average of CPI and PPI" inflation. We find that trimming 9% from each tail of the CPI price-change distribution from the tails of the PPI price-change distribution, yields an efficient estimator of core inflation" for these two series, although lesser trims also produce substantial efficiency gains. Historically the optimal trimmed estimators are found to be nearly 23% more efficient (in terms of root-mean-square error) than the standard mean CPI Moreover, the efficient estimators are robust to sample period and to the definition of the" presumed underlying long-run trend in inflation.

The Seasonality of Consumer Prices

In this paper, we reevaluate the evidence of seasonality in prices which we find to be substantially greater than previous research has indicated. That is, seasonal price movements have become more prominent in the relatively stable inflation environment that has prevailed since 1982. One main conclusion is drawn from this analysis: The amount of seasonality in prices differs greatly by item, making it difficult to generalize about seasonal price movements. A casual reading fails to reveal an easily identifiable origin of the seasonal variation of prices. That is, seasonality in consumer prices is predominantly idiosyncratic in nature, a result that contrasts with studies demonstrating a common seasonal cycle in real economic variables. This finding has an important practical implication: Given the selective, disaggregated approach taken by the Bureau of Labor Statistics to adjust data seasonally, the existence of idiosyncratic seasonality increases the likelihood of allowing noise in the aggregate CPI at a seasonal frequency. This argues in favor of seasonally adjusting the index after aggregation.

Introducing database communication technologies for TED replication in multi-domain networks

In multi-domain transport networks, exchange of Traffic Engineering information is required to enable effective end-to-end service provisioning and restoration by efficiently utilizing network resources. So far, several solutions have been proposed by the communication community such as the Hierarchical Path Computation Element (H-PCE) architecture. Using the H-PCE architecture a parent PCE is responsible for inter-domain path computation, while a dedicated child PCE performs intra-domain path computation within each domain. However, this approach can introduce scalability concerns especially under dynamic traffic condition such as during restoration because all path computation procedures are coordinated by the parent PCE and may require the exchange of many control messages. This paper proposes a standard communication among database systems located at the child PCEs, to exchange and share YANG-based Traffic Engineering information in multi-domain networks. By exploiting currently available database technologies, scalable and predictable performance is demonstrated for both replication mechanisms among child PCEs and information retrieval from the stored databases. Thus, this proposal enables the sharing of intra-domain information at each cPCE that can be locally used, upon failure, to speed-up the recovery procedure

Atomic force microscopy of bacteria from periodontal subgingival biofilm: Preliminary study results

OBJECTIVE: Atomic force microscope (AFM) is a technology that allows analysis of the nanoscale morphology of bacteria within biofilm and provides details that may be better useful for understanding the role of bacterial interactions in the periodontal disease. MATERIAL AND METHODS: Five patients with periodontal ≥5 mm pockets diagnosed as generalized periodontitis and five patients with slight gingivitis were selected for the investigation. Bacteria biofilms were collected and morphologically investigated by AFM application. RESULTS: The investigation revealed how periodontitis bacteria are characterized by specific morphologic features of the cell wall. The major representative species of bacteria causing periodontal diseases have been reproduced by a three-dimensional reconstruction showing the bacteria surface details. CONCLUSIONS: The presence of complex glycocalyx structures, bacteriophage-like vesicles, spirochetes (classic and cystic morphology) and bacterial co-aggregation has been identified by the AFM analysis. The results suggest that AFM is a reliable technique for studying bacterial morphology and for examining microbial interactions in dental plaque

Asset Prices in the Measurement of Inflation

The debate over including asset prices in the construction of an inflation statistic has attracted renewed attention in recent years. Virtually all of this (and earlier) work on incorporating asset prices into an aggregate price statistic has been motivated by a presumed, but unidentified transmission mechanism through which asset prices are leading indicators of inflation at the retail level. This paper takes an alternative, longer-term perspective on the issue and argues that the exclusion of asset prices introduces an excluded goods bias in the computation of the inflation statistic that is of interest to the monetary authority. This idea is implemented using a relatively modern statistical technique, a dynamic factor index. This statistical algorithm allows researchers to see through the excessively noisy asset price data that have frustrated earlier researchers who have attempted to integrate these prices into an aggregate measure