Cereal Production Volatility, National Commodity Availability and Dietary Indicators in Ireland: A Descriptive Time-Series Analysis

Abstract

Background: National commodity availability can vary differently from domestic production and processed dietary indicators. This descriptive ecological time-series study distinguishes short-term volatility from whole-period dispersion and avoids causal claims. Methods: We an-alysed 14 annual observations of Irish national availability for cereals excluding beer, bovine meat and milk excluding butter (2010–2023), an official Central Statistics Office (CSO) princi-pal-cereal production series for the same period, and 13 matched observations for four processed dietary indicators (2010–2022). The primary volatility measure was the sample standard devia-tion of annual logarithmic changes; median absolute change, log-linear detrending and a seg-mented milk trend were sensitivity analyses. Commodity–diet associations were examined using 12 paired annual changes. Results: Annual-growth volatility was 5.75% for cereal availability, 7.10% for bovine meat and 15.96% for milk. Principal-cereal production volatility was 17.36%, compared with 5.75% for cereal availability (attenuation ratio, 0.33; annual-change correlation, −0.08). Dietary indicators were heterogeneous: volatility was 0.85% for diet diversity, 3.25% for total dietary intake, 4.16% for vegetables and 22.78% for pulses. The all-zero dietary cereal series was excluded as invalid. Conclusions: Lower variability in cereal availability is consistent with attenuation between production and national availability, but different commodity scopes and unavailable trade and stock components prevent attribution to trade buffering. The dietary results show no consistent commodity–diet association. Rural resilience was not measured.