The Sensitive Price Indicator (SPI) based weekly inflation surged 0.55 percent, after going down for three weeks in a row. According to data released by the Pakistan Bureau of Statistics (PBS) on Friday, the SPI-based weekly inflation for the week ended on December 16, 2021 for the combined consumption group witnessed o.55 percent increase, while it went 19.49 percent up on a year-on-year (YoY) basis. According to the PBS, the combined index was at 168.16 on December 16, 2021 as compared to 167.24 on December 9, 2021 while the index was recorded at 140.73 a year ago on December 17, 2020. The SPI is computed on a weekly basis to assess the price movements of essential commodities at a shorter interval of time so as to review the price situation in the country. The SPI comprises 51 essential items and the prices are being collected from 50 markets in 17 cities of the country. During the week under review, out of 51 items, prices of 17 (33.34%) items increased, prices of (29.41%) items decreased, and prices of 19 (37.25%) items remained stable. The SPI for the current week recorded an increase in the prices of food items including pulse Masoor (4.11%), salt (3.70%), pulse gram (2.08%), bananas (1.69%), mustard oil (1.35%), pulse Mash (1.32%), and non-food items including electricity for Q1 (10.37%) and washing soap (1.23%), with joint impact of (1.55%) into the overall SPI for combined group of (0.55%). On the other hand, a decrease was observed in the prices of potatoes (15.52%), tomatoes (12.65%), chicken (5.94%), onions (3.94%), diesel (3.48%), petrol (3.40%), eggs (1.69%), gur (1.34%), sugar (1.29%), chilies powdered (0.57%), beef (0.54%), pulse Moong (0.37%), rice basmati broken (0.20%), mutton (0.15%) and wheat flour (0.04%). According to the PBS data, the year on year trend depicts an overall increase of 19.49%, with increase in electricity for Q1 (83.95%), LPG (65.26%), cooking oil 5-litre (60.37%), vegetable ghee 1-kg (57.56%), vegetable ghee 2.5-kg (55.62%), mustard oil (55.60%), washing soap (45.75%), petrol (35.42%), chillies powdered (32.24%), pulse Masoor (29.52%) and diesel (26.72%), while major decrease was observed in the prices of onions (28.72%), pulse Moong (24.87%), chicken (16.09%), tomatoes (14.76%), potatoes (14.58%) and eggs (9.86%). The weekly SPI percentage change by income groups showed that SPI across all quantiles increased ranging between 0.11 percent and 0.98 percent. The lowest income group witnessed a weekly increase of 0.45 percent while the highest income group witnessed a weekly decrease of 0.30 percent. On a yearly basis, analysis of SPI change across different income segments showed that SPI increased across all quantiles ranging between 17.59 percent and 21.42 percent. Yearly inflation for the lowest income group increased by 21.42 percent while the highest income group recorded an increase of 19.46 percent.