تجارت منطقه ای، سیاست های دولت و امنیت غذایی: شواهد اخیر از زامبیا

Given heavy dependence on rainfed maize production, countries in East and Southern Africa must routinely cope with pronounced production and consumption volatility in their primary food staple. Typical policy responses include increased food aid flows, government commercial imports and stock releases, and tight controls on private sector trade. This paper examines recent evidence from Zambia, using a simple economic model to assess the likely impact of maize production shocks on the domestic maize price and on staple food consumption under alternative policy regimes. In addition to an array of public policy instruments, the analysis evaluates the impact of two key private sector responses in moderating food consumption volatility – private cross-border maize trade and consumer substitution of an alternate food staple (cassava) for maize. The analysis suggests that, given a favorable policy environment, private imports and increased cassava consumption together could fill roughly two-thirds of the maize consumption shortfall facing vulnerable households during drought years.

Maize, Africa’s number one food staple, provides over half of all calories consumed in Zambia. Yet dependence on rainfed maize production leads to highly volatile output from 1 year to the next, in Zambia as in many parts of Sub-Saharan Africa (Fig. 1). Given erratic rainfall, and less than 5% of cropped land under irrigation, Zambia’s maize crop fails to satisfy national market demand, on average, in 1 year out of 3. In years of poor harvests, when drought, reduced planting area, or input supply bottlenecks constrict output, Zambia has imported maize. In good harvest years, Zambia produces a maize surplus, enabling the country to export maize. Given this pronounced production volatility, trade becomes a valuable tool for stabilizing national food supplies and prices.

Open borders offer a financially inexpensive means of reducing the domestic price volatility of staple foods. The import parity price sets an upper bound, while export parity sets a floor below which prices will not fall, assuming private traders enjoy the freedom to import and export maize when market conditions permit. The alternative policy of closing borders in small markets such as Zambia invites the prospect of significant price volatility. Under normal production fluctuations, a closed border can easily lead to price volatility in the range of 100% from 1 year to the next.