Decomposing inflation

As U.S. core inflation measures have declined in recent years, analysts have renewed their efforts to understand inflation dynamics. A common approach to this issue is to make inferences about how price changes of major components affect the aggregate inflation rate. This article takes a more rigorous approach, calculating and plotting the precise contributions of major consumer expenditure categories to core inflation measures over time. ; This technique has distinct advantages. It highlights the underlying trends in inflation, enabling analysts to make more informed inferences about the near-term direction of inflation. It also allows analysts to distinguish broad-based changes in inflation from changes due to relative price movements of a few components. ; The analysis focuses on the core components of the consumer price index (CPI) and the personal consumption expenditures price index (PCEPI). Over the long term, the authors note, the composition of core services inflation has remained relatively stable while the composition of core goods inflation has changed dramatically. Over the 2002–03 period, movements in core inflation measures resulted mainly from significant relative price changes of two components that were persistent enough to alter the path of core inflation for a sustained period, the authors conclude. ; The results of this study highlight the importance of gauging the impact of relative changes in a low-inflation environment and suggest that recent concern about overall price deflation was perhaps overstated.Inflation (Finance)

Mixed exciton–charge-transfer states in photosystem II: Stark spectroscopy on site–directed mutants

AbstractWe investigated the electronic structure of the photosystem II reaction center (PSII RC) in relation to the light-induced charge separation process using Stark spectroscopy on a series of site-directed PSII RC mutants from the cyanobacterium Synechocystis sp. PCC 6803. The site-directed mutations modify the protein environment of the cofactors involved in charge separation (PD1, PD2, ChlD1, and PheD1). The results demonstrate that at least two different exciton states are mixed with charge-transfer (CT) states, yielding exciton states with CT character: (PD2δ+PD1δ−ChlD1)∗673nm and (ChlD1δ+PheD1δ−)∗681nm (where the subscript indicates the wavelength of the electronic transition). Moreover, the CT state PD2+PD1− acquires excited-state character due to its mixing with an exciton state, producing (PD2+PD1−)δ∗684nm. We conclude that the states that initiate charge separation are mixed exciton-CT states, and that the degree of mixing between exciton and CT states determines the efficiency of charge separation. In addition, the results reveal that the pigment-protein interactions fine-tune the energy of the exciton and CT states, and hence the mixing between these states. This mixing ultimately controls the selection and efficiency of a specific charge separation pathway, and highlights the capacity of the protein environment to control the functionality of the PSII RC complex