This study investigates the asymmetric effects of economic policy uncertainty (EPU) on food security in Nigeria, utilizing annual time series data from 1970 to 2021. The study used descriptive statistics, unit root tests, the nonlinear autoregressive distributed lag (NARDL) model and its associated Bounds tests to analyze the data. The analysis reveals that adult population, environmental degradation, exchange rate uncertainty (EXRU), financial deepening, food security (FS), government expenditure in agriculture uncertainty (GEAU), inflation, and interest rate uncertainty (INRU) exhibit positive mean values over the period, with varying degrees of volatility. Cointegration tests indicate a long-term relationship between EPU variables (GEAU, INRU, and EXRU) and food security. The study finds that cumulative positive and negative EPU variables have significant effects on food security in the short run. Specifically, negative GEAU, positive INRU, positive and negative EXRU have significant effects in the short run. In the long run, negative GEAU, positive and negative EXRU have significant effects on food security. Additionally, the research highlights asymmetric effects, showing that the influence of GEAU and EXRU on food security differs in the short- and long-run. The study underscores the importance of increased government expenditure on agriculture, control of exchange rate and interest rate uncertainty, and the reduction in economic policy uncertainty to mitigate risks in the agricultural sector and enhance food security. Recommendations include strategies to stabilize exchange rates to safeguard food supply and overall food security.

中文翻译：

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经济政策不确定性对尼日利亚粮食安全的不对称影响

本研究利用 1970 年至 2021 年的年度时间序列数据，调查了经济政策不确定性 (EPU) 对尼日利亚粮食安全的不对称影响。该研究使用了描述性统计、单位根检验、非线性自回归分布滞后 (NARDL) 模型及其模型关联的边界测试来分析数据。分析显示，成年人口、环境退化、汇率不确定性（EXRU）、金融深化、粮食安全（FS）、政府农业支出不确定性（GEAU）、通货膨胀和利率不确定性（INRU）在期间，有不同程度的波动。协整检验表明 EPU 变量（GEAU、INRU 和 EXRU）与粮食安全之间存在长期关系。研究发现，累积的正负EPU变量在短期内对粮食安全有显着影响。具体来说，负GEAU、正INRU、正EXRU和负EXRU在短期内具有显着影响。从长远来看，负GEAU、正负EXRU对粮食安全有显着影响。此外，研究还强调了不对称效应，表明 GEAU 和 EXRU 对粮食安全的影响在短期和长期是不同的。该研究强调了增加政府农业支出、控制汇率和利率不确定性以及减少经济政策不确定性对于减轻农业部门风险和加强粮食安全的重要性。建议包括稳定汇率以保障粮食供应和整体粮食安全的战略。