The impacts of economic policy uncertainties on agriculture export

Figures & data

Table 1. Empirical literature on EPU-trade nexus.

Authors and year	Period	Methodology	Findings
Tunç et al. (2023)	1992- 2021	A Time-varying Granger Causality test	Causality running from EPU to agricultural raw materials
Deuss (2017)	2007- 11	An Error Correction Model	Export bans affect domestic and international markets’ prices.
Hu and Liu (2021)	2002-2021	Time-varying TVP-SV-VAR Model	The global EPU and domestic China’s EPU have heterogenous effects on China’s exports.
Li and Li (2021)	2001- 2019	Time-Varying Parameter Stochastic Volatility Vector Autoregression	EPU has adverse effects on the economic performance of grain imports.
Wen et al., 2021	1998 - 2020	The Nonlinear Autoregressive Distributive Lag Model	EPU has adverse and significant effects on food prices.
Zhang and Qu (2022)	2005- 2020	The Survival Analysis	EPU has diverse effects on imports of varies agricultural food commodities in China.
Zhao (2022)	2000–2014	Gravity Model	Elevated EPU of domestic and destination countries results in manufacturing trade decline.
Jia et al. (2020)	2002-2016	Gravity model	The negative link between EPU and the export of a country.
Constantinescu et al. (2020)	1995 − 2018	fixed effects	The substantially significant adverse effect of EPU on trade growth.
Crowley et al. (2018)	2000 − 2009	A Linear Probability Model	Elevated trade uncertainty makes firms less likely to enter new foreign markets and more likely to exit established ones.
Greenland et al. (2019)	1995–2013	Gravity Specification	Increases in policy unpredictability cut the magnitude of trade and the probability of trade.
Borojo et al. (2021)	2000–2019	Gravity Model	The domestic and destination countries’ EPU adversely affects countries’ trade performance.
Borojo et al. (2023)	1991–2019	Pooled Mean Group Autoregressive Distributed Lag Estimator	EPU adversely impacts green growth in emerging economies.
Li (2020)	1987-2017	Cross-sectional Analysis	A positive connection between EPU and the frequency and volume of insider trades.
Gholipour (2019)	1996 − 2016	Panel Vector Autoregression (PVAR) and Dynamic Least Squares	Increasing EPU significantly decreases the fixed investment of countries.
Liu et al. (2024)	2011–2016	Fixed Effects Regression	Escalation in EPU due to external shocks adversely affects firms’ export recovery performance.
Sui et al. (2022)	2002-2012	The Difference-in-Difference, Two-way Fixed	Reducing TPU enhances the export product quality of countries.
Carballo et al. (2022)	2003–2011	The Structural Model	A larger extensive margin effect in destinations with no trade agreement with the U.S. during policy uncertainty.
Yayi (2023)	1997–2020	Gravity Model	Domestic and foreign policy uncertainties negatively influence exports, imports, and aggregate trade performance.
Yu et al. (2023)	2000-2021	Quantile on Quantile	The robust and heterogenous connection between food and oil prices nexus in China across the quantiles.
Yan et al. (2022)	1997–2017	Bayesian Vector Autoregression	China’s real economy, including trade performance, is adversely affected by U.S. TPU.
Zhang et al. (2022)	2001–2019	Panel Model	TPU of the U.S. is one of the trade barriers to China’s export performance.

Table 2. The effects of EPU on the overall flow of trade.

Variables	(I) Aggregate	(II) Aggregate	(III) Agriculture	(IV) Agriculture
GDP per capita_i,t (log)	0.723*** (0.117)	0.730*** (0.122)	0.678*** (0.126)	1.012*** (0.170)
GDP per capita_j,t (log)	1.032*** (0.079)	0.909*** (0.127)	0.740*** (0.074)	1.327*** (0.158)
population_i,t (log)	0.748*** (0.082)	0.692*** (0.119)	−0.020 (0.057)	0.633*** (0.089)
population_j,t (log)	0.791*** (0.071)	0.844*** (0.129)	0.864*** (0.071)	1.167*** (0.116)
RTA_ij	0.503*** (0.135)	1.636*** (0.275)	0.365** (0.160)	2.678*** (0.289)
common_currency_ij	−0.102 (0.186)		0.441*** (0.150)
distance_ij	−0.842*** (0.064)		−0.972*** (0.074)
real exchange_rate_i,t (log)	0.594*** (0.195)	0.408* (0.226)	−1.922*** (0.264)	−2.276*** (0.328)
tariff_i,t (log)	0.031* (0.018)	0.008 (0.015)	−0.047*** (0.020)	−0.165*** (0.028)
EPU_i,t +1(log)	−0.491** (0.205)	−0.277*** (0.047)	−0.218*** (0.066)	−0.136*** (0.045)
constant	0.016 (1.681)	−7.049*** (2.391)	10.429*** (1.391)	−11.325*** (2.092)
Exporter_time fixed effects	Yes	Yes	Yes	Yes
Importer_time fixed effects	No	Yes	No	Yes
Country pair_fixed effects	No	Yes	No	Yes
Obs.	20140	20140	20141	20141
R2	0.94	0.808	0.918	0.918

Notes: *** shows significance at 1%, ** indicates significance at 5%, * significant at 10%, country-pair clustered standard errors are reported in parentheses, i=1… 60 and 𝑗=1… 60 depict the reporter and partner countries, correspondingly.

Table 3. The impacts of EPU on agriculture export based on countries’ heterogeneity.

	High-income	Emerging
GDP per capita_i,t (log)	0.744** (0.332)	1.904*** (0.465)
GDP per capita_j,t (log)	1.020*** (0.080)	1.099*** (0.223)
population_i,t (log)	0.420*** (0.093)	1.183*** (0.212)
population_j,t (log)	1.089*** (0.049)	1.362*** (0.239)
regional_trade_agreement_ij	2.519*** (0.094)	2.365*** (0.502)
real exchange_rate_i,t (log)	−1.780*** (0.240)	−2.585*** (0.677)
tariff_i,t (log)	0.088 (0.081)	0.007 (0.023)
EPU_i,t +1(log)	−0.488*** (0.133)	−0.303*** (0.104)
constant	−7.269*** (1.726)	−23.493*** (5.922)
Exporter_time FE.	Yes	Yes
Importer_time FE.	Yes	Yes
Pair_FE	Yes	Yes
Obs.	7721	12420
R2	0.934	0.918

Notes: *** represents significance level at 1%, ** indicates significance at 5%, * shows significance at 10%, country-pair clustered standard errors are reported in parentheses, i=1…,60 and j=1…,60 show the reporter and partner countries, correspondingly.

Table 4. The moderating role of logistics performance and trade agreements.

Variables	(Ia)	(Ib)	(IIa)	(IIb)
GDP per capita_i,t (log)	1.754*** (0.333)	1.369*** (0.299)	1.637*** (0.106)	1.731*** (0.129)
GDP per capita_j,t (log)	1.130*** (0.178)	1.124*** (0.144)	1.388*** (0.075)	0.993*** (0.094)
population_i,t (log)	0.814*** (0.195)	0.468*** (0.129)	0.932*** (0.083)	0.515*** (0.121)
population_j,t (log)	0.904*** (0.127)	0.941*** (0.109)	1.175*** (0.067)	0.949*** (0.083)
real exchange_rate_i,t (log)	−2.723*** (0.979)	−2.776*** (0.592)	−3.189*** (0.206)	−2.960*** (0.246)
tariff_i,t (log)	−0.125** (0.056)	−0.017 (0.066)	0.014 (0.026)	−0.324*** (0.054)
EPU_i,t +1(log)	−0.357 (0.467)	−2.539*** (0.667)	−0.497*** (0.141)	−0.345*** (0.133)
RTAij	0.880** (0.387)	−0.007 (0.385)	2.678*** (0.082)	2.678*** (0.082)
RTAij* EPU_i,t +1(log)		1.629*** (0.381)
LPIi			3.991*** (0.357)	−3.093*** (0.376)
LPI* EPU_i,t +1(log)				0.110** (0.056)
cons	−11.290*** (3.220)	−5.643*** (1.958)	−19.423*** (1.655)	−4.610* (2.574)
Exporter_time fixed effects	Yes	Yes	Yes	Yes
Importer_time fixed effects	Yes	Yes	Yes	Yes
Country pair_fixed effects	Yes	Yes	Yes	Yes
Obs.	20141	20141	20141	20141
R2	0.708	0.824	0.917	0.917

Notes: *** shows a significance level at 1%, ** indicates a significance level at 5%, * significant at 10%, country-pair clustered standard errors are reported in parentheses, i=1,…,60 and j=1,…,60 indicate the reporter and partner countries, respectively.

Table 5. The moderating role of GDP per capita.

Variables	Agriculture export
GDP per capita_i,t (log)	1.627*** (0.179)
GDP per capita_j,t (log)	0.840*** (0.146)
population_i,t (log)	0.361*** (0.114)
population_j,t (log)	0.821*** (0.146)
RTA_ij	1.909*** (0.268)
real exchange_rate_i,t (log)	−1.617*** (0.391)
tariff_i,t (log)	−0.045 (0.032)
EPU_i,t +1(log)	−0.671*** (0.117)
GDP per capita_i,t (log)* EPU_i,t +1(log)	0.060*** (0.022)
Constant	−3.062 (2.486)
Exporter_time FE.	Yes
Importer_time FE.	Yes
Pair_FE	Yes
Obs.	20141
R2	0.796

Notes: *** is to represent significance at 1%, ** shows significance level at 5%, * represents significance at 10%, country-pair clustered standard errors are reported in parentheses, i=1,…,60 and j=1,…,60 indicate the reporter and partner countries, respectively.

Table 6. The impacts of TPU on agriculture export.

Variables	(I) Aggregate	(II) Aggregate	(III) Agriculture	(IV) Agriculture
GDP per capita_i,t (log)	1.042*** (0.114)	0.731*** (0.123)	0.755*** (0.151)	1.356*** (0.142)
GDP per capita_j,t (log)	1.016*** (0.075)	0.904*** (0.127)	0.740*** (0.074)	1.660*** (0.120)
population_i,t (log)	0.837*** (0.080)	0.690*** (0.119)	0.024 (0.061)	0.786*** (0.107)
population_j,t (log)	0.818*** (0.085)	0.842*** (0.130)	0.864*** (0.071)	1.361*** (0.134)
RTA_ij	0.503*** (0.135)	1.641*** (0.276)	0.365** (0.160)	2.678*** (0.289)
common_currency_ij	−0.102 (0.186)		0.441*** (0.150)
distance_ij	−0.842*** (0.064)		−0.972*** (0.074)
real exchange_rate_i,t (log)	−0.096 (0.235)	0.414* (0.224)	−2.053*** (0.277)	−1.030*** (0.240)
tariff_i,t (log)	−0.050* (0.027)	0.003 (0.018)	−0.055*** (0.018)	0.050 (0.034)
TPU_i,t +1(log)	−0.226*** (0.042)	−0.061*** (0.023)	−0.009** (0.004)	−0.012*** (0.004)
constant	−0.451 (1.545)	−7.118*** (2.423)	9.879*** (1.461)	−20.710*** (2.162)
Exporter_time FE.	Yes	Yes	Yes	Yes
Importer_time FE.	No	Yes	No	Yes
Pair_FE	No	Yes	No	Yes
Obs.	20140	20140	20141	20141
R2	0.940	0.808	0.795	0.917

Notes: *** represents significance at 1%, ** is significance at 5%, * significant at 10%, country-pair clustered standard errors are reported in parentheses, i=1,…,60 and j=1,…,60 indicate the origin and destination country, respectively.

Table 7. The impacts of TPU on agriculture export based on countries’ heterogeneity.

	Developed	Emerging
GDP per capita_i,t (log)	1.475*** (0.184)	1.713*** (0.420)
GDP per capita_j,t (log)	0.999*** (0.173)	1.099*** (0.223)
population_i,t (log)	0.161** (0.076)	1.320*** (0.249)
population_j,t (log)	0.971*** (0.188)	1.362*** (0.239)
RTA_ij	2.101*** (0.250)	2.365*** (0.502)
real exchange_rate_i,t (log)	−2.144*** (0.168)	−2.276*** (0.598)
tariff_i,t (log)	−0.113** (0.043)	−0.053*** (0.020)
TPU_i,t +1(log)	−0.087 (0.126)	−0.521*** (0.147)
constant	−5.442** (2.688)	−23.494*** (5.922)
Exporter_time FE.	Yes	Yes
Importer_time FE.	Yes	Yes
Pair_FE	Yes	Yes
Obs.	7721	12420
R2	0.791	0.918

Notes: *** significant at 1%, ** significant at 5%, * significant at 10%, country-pair clustered standard errors are reported in parentheses, i=1,…,60 and j=1,…,60 indicate the origin and destination country, respectively.

Figure A1. EPU of developed and emerging countries.

Table A1. Summary statistics of the variables.

Variable	Obs	Mean	Std. Dev	Min	Max
distance_ij	21600	8453.41	5007.78	66.775	19110.10
population_i,t	21600	206181.70	376147.20	3857.70	1400000
population_j,t	21600	206181.70	376147.20	3857.70	1400000
GDP per capita_i,t	21600	24.41	18.84	0.46	67.53
GDP per capita_j,t	21600	24.41	18.84	0.46	67.53
RTAijt	21600	0.24	0.43	0	1
real exchange_rate_i,t	21600	0.96	0.38	0.35	2.61
EPUi,t	21600	0.89	0.74	0	5.37
Comcurij	21600	0.09	0.28	0	1
TPUi,t	21600	4.32	14.82	0	145.62
tariff_ij,t	21600	5.19	3.67	1.04	18.32
Agriceportij,t	21600	994550.80	2766268.00	0	3.13E + 07

Tunç, A., Savaş, S., & Barak, D. (2023). The causality between agricultural raw materials and economic policy uncertainty: evidence from the time- varying granger causality tarimsal hammaddeler ve ekonomi politikasi belirsizliği nedensellik ilişkisi : zamanla değişen granger. 19:1–13.

 Google Scholar

Deuss, A. (2017). Impact of agricultural export restrictions on prices in importing countries. (OECD Food, Agriculture and Fisheries Papers, No. 105). OECD Publishing. https://doi.org/10.1787/1eeeb292-en

 Google Scholar

Hu, G., & Liu, S. (2021). Economic policy uncertainty (EPU) and China’ s export fluctuation in the post-pandemic era : An empirical analysis based on the TVP-SV-VAR Model. Frontiers in Public Health, 9, 788171. https://doi.org/10.3389/fpubh.2021.788171

 PubMed Web of Science ®Google Scholar

Li, Y., & Li, J. (2021). How does China ’s economic policy uncertainty affect the sustainability of its net grain imports? Sustainability, 13(12), 6899. https://doi.org/10.3390/su13126899

 Web of Science ®Google Scholar

Wen, J., Khalid, S., Mahmood, H., & Zakaria, M. (2021). Symmetric and asymmetric impact of economic policy uncertainty on food prices in China : A new evidence. Resources Policy, 74, 102247. https://doi.org/10.1016/j.resourpol.2021.102247

 Web of Science ®Google Scholar

Zhang, R., & Qu, Y. (2022). The impact of U.S. trade policy uncertainty on the trade margins of China’s export to the U.S. Sustainability, 14(22), 15101. https://doi.org/10.3390/su142215101

 Web of Science ®Google Scholar

Zhao, T. (2022). Economic policy uncertainty and manufacturing value-added exports. Engineering Economics, 33(1), 103–114. https://doi.org/10.5755/j01.ee.33.1.27373

 Google Scholar

Jia, F., Huang, X., Xu, X., & Sun, H. (2020). The effects of economic policy uncertainty. Prague Economics Papers, 29, 600–622. https://doi.org/10.18267/j.pep.754

 Web of Science ®Google Scholar

Constantinescu, C., Mattoo, A., & Ruta, M. (2020). Policy uncertainty, trade and global value chains : Some facts, many questions. Review of Industrial Organization, 57(2), 285–308. https://doi.org/10.1007/s11151-020-09772-0

 Web of Science ®Google Scholar

Crowley, M., Meng, N., & Song, H. (2018). Tariff scares: Trade policy uncertainty and foreign market entry by Chinese firms. Journal of International Economics, 114, 96–115. https://doi.org/10.1016/j.jinteco.2018.05.003

 Web of Science ®Google Scholar

Greenland, A., Ion, M., & Lopresti, J. (2019). Exports, investment and policy uncertainty. Canadian Journal of Economics/Revue Canadienne D'économique, 52(3), 1248–1288. https://doi.org/10.1111/caje.12400

 Web of Science ®Google Scholar

Borojo, D. G., Yushi, J., & Miao, M. (2021). The impacts of economic policy uncertainty on trade flow. Emerging Markets Finance and Trade, 58(8), 2258–2272. https://doi.org/10.1080/1540496X.2021.1971075

 Web of Science ®Google Scholar

Borojo, D. G., Yushi, J., Miao, M., & Xiao, L. (2023). The impacts of economic policy uncertainty, energy consumption, sustainable innovation, and quality of governance on green growth in emerging economies. Energy & Environment, 0958305X2311739. https://doi.org/10.1177/0958305X231173997

 Web of Science ®Google Scholar

Li, X. (2020). The impact of economic policy uncertainty on insider trades: A cross-country analysis. Journal of Business Research, 119, 41–57. https://doi.org/10.1016/j.jbusres.2020.07.025

 Web of Science ®Google Scholar

Gholipour, H. F. (2019). The effects of economic policy and political uncertainties on economic activities. Research in International Business and Finance, 48, 210–218. https://doi.org/10.1016/j.ribaf.2019.01.004

 Web of Science ®Google Scholar

Liu, Q., Li, Z., & Wang, Y. (2024). The heterogeneous impact of economic policy uncertainty on export recovery of firms: The role of the regional digital economy. Regional Science Policy & Practice, 16(5), 100044. https://doi.org/10.1016/j.rspp.2024.100044

 Google Scholar

Sui, H., Li, X., Raza, A., & Zhang, S. (2022). Impact of trade policy uncertainty on export products quality: New evidence by considering role of social capital. Journal of Applied Economics, 25(1), 997–1024. https://doi.org/10.1080/15140326.2022.2087341

 Web of Science ®Google Scholar

Carballo, J., Handley, K., & Limão, N. (2022). Economic and policy uncertainty: Aggregate export dynamics and the value of agreements. Journal of International Economics, 139, 103661. https://doi.org/10.1016/j.jinteco.2022.103661

 Web of Science ®Google Scholar

Yayi, C. L. (2023). Economic policy uncertainty and trade: does export sophistication matter? Applied Economics, 56(2), 169–185. https://doi.org/10.1080/00036846.2023.2166672

 Web of Science ®Google Scholar

Yu, Y., Peng, C., Zakaria, M., Mahmood, H., & Khalid, S. (2023). Nonlinear effects of crude oil dependency on food prices in China: Evidence from quantile-on-quantile approach. Journal of Business Economics and Management, 24(4), 696–711. https://doi.org/10.3846/jbem.2023.20192

 Web of Science ®Google Scholar

Yan, H., Xiao, W., Deng, Q., & Xiong, S. (2022). Analysis of the impact of U.S. trade policy uncertainty on China based on Bayesian VAR model. Journal of Mathematics, 2022, 1–8. https://doi.org/10.1155/2022/7124997

 Web of Science ®Google Scholar

Zhang, Z., Brizmohun, R., Li, G., & Wang, P. (2022). Does economic policy uncertainty undermine stability of agricultural imports ? Evidence from China. PloS One, 17(3), e0265279. 1–17. https://doi.org/10.1371/journal.pone.0265279

 PubMed Web of Science ®Google Scholar

Data availability statement

The data supporting this study’s findings are available from the corresponding author, TSG, upon reasonable request.