Does synchronization of biennial bearing in olive production exist?: Evidence from the Mediterranean countries

Abstract

Since the time of ancient civilizations, the synchronization of alternate (or biennial) bearing of olive has been a well-known phenomenon in the Mediterranean region. The pattern of alternate bearing has been synchronized in certain orchards or nearby regions where horticultural trees grow. Although synchronization in olive production in the Mediterranean region has been observed, empirical evidence is missing. This study aims to determine whether the biennial bearing of olive production is synchronized. Using country-level panel data of olive production in the Mediterranean countries from 1992 to 2018, we estimated a spatial regression model of olive production using a geographically weighted matrix. After controlling for climatic factors that may influence olive production, we examined whether geographical proximity significantly explains the variation in olive production level, yield, and pattern of alternate bearing. Results suggest that the spatial autoregressive coefficient is positive and statistically significant. We conclude that geographical proximity between countries significantly explains the variation of the level and biennial pattern of olive production, indicating the existence of biennial bearing synchronization.