The U.S. Bureau of Economic Analysis (BEA, an agency under the Department of Commerce responsible for compiling key economic data) plans to adjust the calculation methods for three categories in the Personal Consumption Expenditures Price Index (PCE, the Federal Reserve's most closely watched measure of inflation, which tracks changes in consumer prices for goods and services, has a broader coverage than the Consumer Price Index (CPI), and its weights are adjusted according to consumption habits) starting with the August data to be released in September: computer software, legal service fees, and investment advisory fees. The software and investment advisory categories have seen significant price increases over the past year, which some economists believe has pushed up the overall inflation reading. After the adjustment, the core PCE inflation rate (a more stable indicator excluding food and energy) is expected to be lowered by about 0.2 percentage points. Currently, the June PCE inflation rate is 3.7%, and the core rate is 3.3%, still well above the Federal Reserve's 2% target. These changes are technical updates designed to more accurately reflect price changes in areas that are difficult to measure and do not affect the CPI published independently by the Department of Labor. This adjustment has attracted political attention against the backdrop of persistently high inflation and the Trump administration's previous dismissal of the head of the Bureau of Labor Statistics and disbanding of related expert advisory committees due to poor employment data. Senator Elizabeth Warren, a Democrat from Massachusetts, sent a letter to the Department of Commerce and the BEA on Thursday morning, questioning the details of the PCE adjustment scheduled to take effect next month. She emphasized that the BEA has an "obligation to explain to the public" the reasons and processes behind these decisions. Warren pointed out that in the tense atmosphere of politicizing economic data, the fine-tuning of statistical methods needs to be examined more deeply. A BEA spokesperson declined to comment, stating that the agency previously stated the adjustments were to improve accuracy. The current head of the BEA, Wipin Arora, is a civil servant who joined the administration during the Biden administration. There is currently no evidence that the adjustments are politically motivated. How exactly will the adjustments change, and what will be the impact? Under the new methodology, computer software inflation will no longer be closely linked to hardware prices (hardware prices have soared during the AI boom); investment advisory costs will also not move in tandem with stock market performance as they have in the existing system. Data sources for legal services will also be adjusted. Overall, these changes could lower the overall inflation reading by about 0.2 percentage points. Even after the adjustments, inflation may still be significantly higher than the 2% target. Federal Reserve Chairman Kevin Warsh has pledged to suppress inflation and hinted at a possible review of the indicators included in the inflation dashboard. What do experts think, and where does the political controversy come from ? Most economists following this issue believe the adjustments are justifiable and will more accurately capture price changes in areas that are difficult to measure. However, the timing is sensitive: the Trump administration had previously influenced statistical agencies, disbanding the expert committee that provided methodological advice. Warren therefore demanded a more transparent explanation. The adjustments will not affect the CPI, only the PCE and its historical data retrospective. Warren also raised concerns about the new data privacy ban. In her letter, Warren also requested the Commerce Department to explain another adjustment: a ban on "noise injection" (a technique that adds random perturbations to statistical data to protect respondents' privacy, thus protecting individual/business information from identification while allowing for the release of more detailed data). She warned that the ban could prevent agencies from releasing highly detailed data in certain situations, such as local employment data for specific industries, thereby affecting government statistics including the decennial census. Overall, this PCE methodology update is part of routine statistical improvements, but it has been amplified in the current political and inflationary environment. The adjusted data will gradually take effect from the end of September, and the market and the Federal Reserve will use it to observe the interest rate path.