Compiling a Lowe-Based Plasma FFB Price Index and Assessing Weight Structure Sensitivity

Officially determined fresh fruit bunch (FFB) prices for plasma smallholders vary across provinces, motivating interprovincial monitoring. This study compiled a Lowe price index for 22 provinces during May 2025–September 2026 and assessed its sensitivity to five alternative weighting scenarios. Monthly provincial prices were arithmetic averages of available daily observations. May 2025 was the price reference period (index = 100), and 2024 crude palm oil (CPO) production from smallholder plantations served as a quantity proxy because plasma FFB production data were unavailable in the dataset. Mean Absolute Percentage Deviation (MAPD) measured differences in index values; Total Variation Distance (TVD) measured differences in provincial weight distributions. The index reached a low of 94.99 in June 2025, a high of 114.19 in April 2026, and 114.16 in September 2026, representing a 14.16% increase from May 2025. MAPD ranged from 0.0039% to 0.0846%, while TVD ranged from 0.46% to 4.99%. The study contributes an interprovincial indicator of officially determined plasma FFB price changes and evidence of limited sensitivity to the weighting scenarios examined. However, CPO-based weights may not represent the plasma FFB production structure, and the index does not measure actual transaction prices or smallholder income.