Variability of Maize Prices in Ghana: A Generalized Additive Mixed Model Approach

Variability of Maize Prices in Ghana: A Generalized Additive Mixed Model Approach

Smart Asomaning Sarpong

Kumasi Technical University

Daniel Asare-Kyei

Kumasi Technical University

Felix Addae

Kumasi Technical University

Dora Melanie Yanchira

Department of Statistics, North Carolina State University, Raleigh, NC, USA

Keywords: Generalized Additive Mixed Models; Maize; Price variability; Markets


Abstract

Maize is grown throughout Ghana, and it is one most common cereal on every market; from

A (Ashaiman market) to Z (Zebila Market). In this study, variability in prices of maize has been studied across 35 major markets in all 16 regions of Ghana. Data for this study were compiled weekly for a 5-year duration (2018–2022), except for a week when no maize was grown, i.e., the off-season. The location, week, and year were recorded, along with the price variations, to facilitate analysis. Generalized Additive Mixed Models were used to uncover patterns, trends, and potential factors influencing price. It is hereby established that the maize price increased smoothly from 2018 to 2020, and rapidly from 2020 to 2022. The Kotokura bamarket, Dambai market, Ho Central market, Tarkwa market, and Goaso markets recorded the highest Maize prices within the 5 years. Further analysis reveals that the location of the market contributes more (51.7%) to price variability than the ‘week’. Again, the average trend of maize prices tends to increase from week 1 in January to 3rd week in June and decrease from the last week in June to 3rd week in December. The Government and other agribusiness interest groups may invest in storage facilities to store maize from June to December to help in price stabilization during the off-season from January to early June. Further research will be needed to explain in detail why market location, far or near the farm gate, accounts for more than 50% of price variability.


Author Biographies

Smart Asomaning Sarpong, Kumasi Technical University

Institute of Research, Innovation and Development – IRID. Kumasi Technical University, KsTU

Daniel Asare-Kyei, Kumasi Technical University

Institute of Research, Innovation and Development – IRID. Kumasi Technical University, KsTU

Felix Addae, Kumasi Technical University

Institute of Research, Innovation and Development – IRID. Kumasi Technical University, KsTU

Dora Melanie Yanchira, Department of Statistics, North Carolina State University, Raleigh, NC, USA

Department of Statistics, North Carolina State University, Raleigh, NC, USA