Berna TÜRKEKUL

Ziraat Fakültesi, Tarım Ekonomisi Bölümü, Tarım Politikası Ve Yayım Anabilim Dalı

Research areas: Agricultural Sciences, Agriculture, Farming Economy, Agricultural Policy and Publication, Agricultural Policy, International Agricultural Trade, Natural Resources and Environmental Economics, Engineering and Technology, Farm Machinery, Energy in Agriculture

Publications

• Beyond income: governance and protein supply drive global food security (2026)
• The expenditure elasticity pattern in section 5.2 is the more easily anticipated of the two principal results; the price responsiveness pattern is the more consequential one. Every estimated own-price elasticity in the Nigerian system is negative under both the Marshallian and the Hicksian definition, so the law of demand and compensated negativity hold for every food group estimated. Within the set of goods with statistically confirmed negative compensated own-price responses, cereals (−0.51) are the least price-responsive, consistent with their role as a dietary staple for which households have limited substitution opportunities even when compensated for the income loss. Cereals are simultaneously the largest single budget share in the Nigerian food basket, at 24.9 percent. A food group that is both large in the budget and inelastic in demand is precisely the combination that produces large welfare losses when its price rises, because households cannot reduce their cereal purchases proportionately to a price increase without a correspondingly large reduction in food intake, and the budget share affected is large to begin with. The welfare estimates in section 4.5 quantify this mechanism under the assumption of full price transmission from global to domestic cereal markets, and using long-run elasticities that likely understate the short-run response to a sudden price spike; both qualifications are discussed in section 5.6. A cereal price increase of the magnitude associated with the 2022 disruption of Ukrainian and Russian grain exports, seventy percent, generates a second-order compensating variation equal to 11.4 percent of food expenditure and 7.1 percent of total household expenditure for the average household in this sample. The fifty percent increase comparable to the 2010-11 price spike costs 9.1 percent of food expenditure and 5.6 percent of total expenditure, and the thirty percent increase comparable to the 2008 crisis costs 6.1 percent of food expenditure and 3.8 percent of total expenditure. These figures are computed after allowing for the compensated substitution toward vegetables, fruit, and other food groups documented in section 4.4. The central argument that follows from placing the expenditure and price results side by side is that Nigerian households have substitution opportunities available to them, the positive compensated cross-price elasticities in the Hicksian matrix are direct evidence of this, but those opportunities are not large enough to prevent a major cereal price shock from imposing a substantial welfare cost, because the good in question is both budget-dominant and demand-inelastic. This finding sits within a long empirical literature on staple food prices and household welfare in developing economies. Deaton (1989) uses household survey data from Thailand to show that rice price changes have sharply different welfare consequences for net rice buyers and net rice sellers, a distributional point that this study's aggregate compensating variation estimates do not separately identify but that is a natural next step once a structural demand system of the kind estimated here for Nigeria is in hand. Ivanic and Martin (2008) find that the staple food price increases of the 2008 world food crisis raised poverty among net food-buying households across a sample of low-income countries, and Headey (2011) traces the role of trade policy responses, particularly export restrictions, in amplifying the price shocks that drove those welfare losses. Bellemare (2015) extends the welfare consequences of food price movements beyond household budgets directly, linking food price volatility, as distinct from the price level, to social unrest, which suggests that the welfare costs quantified in section 4.5 may understate the full social cost of cereal price instability if that instability has consequences beyond the household budget constraint modelled here. Gibson (2013) makes the closely related point that household surveys in developing countries generally prioritise collecting living-standards data over the price data needed to measure welfare impacts properly, and that studies ignoring households' coping responses, particularly downgrading food quality to maintain quantity, tend to overstate the welfare harm of rising prices; the Nigerian estimates in this study rely on unit-value-based prices precisely because no separate price survey was available, a limitation discussed further in section 5.6. Hertel and colleagues (2001) take a complementary, general-equilibrium approach, using a global trade model to assess how staple food price variability translates into poverty vulnerability for low-income households across several countries simultaneously, a cross-country perspective this study's single-country structural design does not attempt to replicate. (2026)
• The expenditure elasticity pattern in section 5.2 is the more easily anticipated of the two principal results; the price responsiveness pattern is the more consequential one. Every estimated own-price elasticity in the Nigerian system is negative under both the Marshallian and the Hicksian definition, so the law of demand and compensated negativity hold for every food group estimated. Within the set of goods with statistically confirmed negative compensated own-price responses, cereals (−0.51) are the least price-responsive, consistent with their role as a dietary staple for which households have limited substitution opportunities even when compensated for the income loss. Cereals are simultaneously the largest single budget share in the Nigerian food basket, at 24.9 percent. A food group that is both large in the budget and inelastic in demand is precisely the combination that produces large welfare losses when its price rises, because households cannot reduce their cereal purchases proportionately to a price increase without a correspondingly large reduction in food intake, and the budget share affected is large to begin with. The welfare estimates in section 4.5 quantify this mechanism under the assumption of full price transmission from global to domestic cereal markets, and using long-run elasticities that likely understate the short-run response to a sudden price spike; both qualifications are discussed in section 5.6. A cereal price increase of the magnitude associated with the 2022 disruption of Ukrainian and Russian grain exports, seventy percent, generates a second-order compensating variation equal to 11.4 percent of food expenditure and 7.1 percent of total household expenditure for the average household in this sample. The fifty percent increase comparable to the 2010-11 price spike costs 9.1 percent of food expenditure and 5.6 percent of total expenditure, and the thirty percent increase comparable to the 2008 crisis costs 6.1 percent of food expenditure and 3.8 percent of total expenditure. These figures are computed after allowing for the compensated substitution toward vegetables, fruit, and other food groups documented in section 4.4. The central argument that follows from placing the expenditure and price results side by side is that Nigerian households have substitution opportunities available to them, the positive compensated cross-price elasticities in the Hicksian matrix are direct evidence of this, but those opportunities are not large enough to prevent a major cereal price shock from imposing a substantial welfare cost, because the good in question is both budget-dominant and demand-inelastic. This finding sits within a long empirical literature on staple food prices and household welfare in developing economies. Deaton (1989) uses household survey data from Thailand to show that rice price changes have sharply different welfare consequences for net rice buyers and net rice sellers, a distributional point that this study's aggregate compensating variation estimates do not separately identify but that is a natural next step once a structural demand system of the kind estimated here for Nigeria is in hand. Ivanic and Martin (2008) find that the staple food price increases of the 2008 world food crisis raised poverty among net food-buying households across a sample of low-income countries, and Headey (2011) traces the role of trade policy responses, particularly export restrictions, in amplifying the price shocks that drove those welfare losses. Bellemare (2015) extends the welfare consequences of food price movements beyond household budgets directly, linking food price volatility, as distinct from the price level, to social unrest, which suggests that the welfare costs quantified in section 4.5 may understate the full social cost of cereal price instability if that instability has consequences beyond the household budget constraint modelled here. Gibson (2013) makes the closely related point that household surveys in developing countries generally prioritise collecting living-standards data over the price data needed to measure welfare impacts properly, and that studies ignoring households' coping responses, particularly downgrading food quality to maintain quantity, tend to overstate the welfare harm of rising prices; the Nigerian estimates in this study rely on unit-value-based prices precisely because no separate price survey was available, a limitation discussed further in section 5.6. Hertel and colleagues (2001) take a complementary, general-equilibrium approach, using a global trade model to assess how staple food price variability translates into poverty vulnerability for low-income households across several countries simultaneously, a cross-country perspective this study's single-country structural design does not attempt to replicate. (2026)
• Climate Resilience of Mediterranean Maquis Ecosystems: Evidence from Economic Valuation Studies (2026)
• OECD Ülkelerinde Toplumsal Cinsiyet Eşitsizliğinin Ekonomik Büyüme Üzerindeki Etkisi: Dinamik Panel Bulguları (2026)
• Beyond income: governance and protein supply drive global food security (2026)
• Gender inequality and economic growth: An analysis of OECD countries (2025)
• Understanding Why Farmers Leave: Validating Key Indicators for Farm Exit in İzmir, Türkiye (2024)
• Effects of Partial Replacement of Soybean with Local Alternative Sources on Growth, Blood Parameters, Welfare, and Economic Indicators of Local and Commercial Broilers (2024)
• Türkiye’nin Yaş Meyve Ürünlerindeki Rekabet Gücünün İncelenmesi (2023)
• Comparative Advantage of Yarn and Weaving Industries: Evidence for Türkiye and Top Exporters (2023)
• Alternative sustainable broiler feed formulations with local ingredients and Black soldier fly larvae: what do stakeholders think in Turkey? (2022)
• RECENTS TRENDS IN COTTON FIBER MARKET: CURRENT AND FUTURE PROSPECTS (2022)
• MEDICINAL AND AROMATIC PLANTS PRODUCTION, MARKETING AND FOREIGN TRADE (2021)
• Batı Afrika Ülkelerinden Bulgularla Sektörler Arası Bağlantılar Üzerine Bir Hikaye (2021)
• Türkiye’nin pamuk ve pamuklu dokumada uluslararası rekabet gücü: sabit pazar payı ve açıklanmış karşılaştırmalı üstünlük analizi (2021)
• FACTORS AFFECTING THE TURKSIH FARMERS' DECISION TO QUIT FARMING (2020)
• Türkiye’de 2000 Yılı Sonrası Uygulanan Tarım Politikaları (2019)
• Türkiye ile Türk Cumhuriyetleri Arasındaki Ekonomik İlişkilerin Dış Ticaret Açısından Değerlendirilmesi (2019)
• Süt Sığırcılığı Yapan İşletmelerin Genel Özelliklerinin Belirlenmesi: İzmir İli Ödemiş ve Tire İlçeleri Örneği (2019)
• Türkiye’de Uygulanmakta Olan Hayvancılık Desteklemelerinin Süt Sığırcılığı Yapan İşletmelere Etkisi: İzmir İli Örneği (2019)
• Determination Of Forest Fire Monitoring Points Using 0-1 Integer Programming (2018)
• ARE POLAND AND TURKEY RIVALS IN THE EU AGRICULTURAL MARKET? (2018)
• Distribution Of Tobacco Products With Integer Linear Programming (2018)
• The Impact of Animal Husbandry Policies on Dairy Farms: The Case of Izmir Province (2018)
• Relationship between Production and Price of Potatoes in Turkey: A Distributed Lag Model Analysis (2018)
• Kırsal ve Ormanlık Alanlarının Rekreaasyon Faaliyetlerine Ayrılmasında Doğrusal Programlama Kullanımı (2017)
• Assessing Impact of Government Policies on the Competitiveness of Turkish Corn production (2017)
• Türkiye’de Üreticilerin Tarımsal Desteklerden Faydalanma Durumu Üzerineİnceleme (2017)
• The Impact of Turkish Agricultural Policy on Competitiveness of Cotton Production (2017)
• Doğrusal Programlama ile Tütün Mamülleri Dağıtımının Minimizasyonu: Akhisar Örneği (2017)
• Rural Poverty in Turkey: The Role of Agriculture (2017)
• Sustainability of cotton production in Turkey: An analysis of efficiency using data envelopment analysis (2017)
• Using Linear Programming to Allocate Rural and Forest Areas to Recreational Activities (2017)
• Türkiye’de Üreticilerin Tarımsal Desteklerden Faydalanma Durumu Üzerine İnceleme (2017)
• Evaluating Ecological Footprint in Turkey: School of Tobacco Expertise Students Case Study (2017)
• Minimization of Distrubition of Tobacco Products Using Linear Programming: Akhisar Province Case Study (2017)
• Zeytinyağı Üretiminde Sürdürülebilirliğin Ve Rekabetçiliğin Güçlendirilmesi (2016)
• THE CONCENTRATION ANALYSIS OF AGRICULTURAL SECTOR IN TURKEY: ARE THERE ANY CHANGES IN THE PERIOD 2010 - 2015? (2016)
• The Impact of Turkish Agricultural Policy on Competitiveness of Oilseed Sunflower in Western Marmara Region Turkey (2016)
• Exploring the relationship between agricultural electricity consumption and output: New evidence from Turkish regional data (2016)
• CO2 emissions, real output, energy consumption, trade, urbanization and financial development: testing the EKC hypothesis for the USA (2015)
• Türkiye de Enflasyon İşsizlik İlişkisinin Analizi (2014)
• Dünya Tarım Ürünleri Piyasalarının Değişen Dinamikleri ve Türkiye nin Rekabet Gücü (2014)
• International Competitiveness of Olive Oil Sector The Case of International Olive Council IOC (2014)
• Are The CEFTA Countries Competitive At The EU Market (2013)
• Maksimum Kalıntı Limitlerinin belirlenmesi çalışmalarında kullanılmak üzere Türkiye de yetiştirilen tarımsal ürünlerin majör ve minör olarak sınıflandırılması (2013)
• Maksimum Kalıntı Limitlerinin Belirlenmesi Çalışmalarında Kullanılmak Üzere Türkiye de Yetiştirilen Tarımsal Ürünlerin Majör ve Minör Olarak Sınıflandırılması (2013)
• Fresh Fruit and Vegetable Consumption in Turkey Classification As Major Minor Crops and Scope For Determination of National Maximum Residue Limits (2013)
• Why Farmers Quit from Farming (2013)
• Univariate Modelling of Energy Consumption in Turkish Agriculture (2013)
• The Factors Effecting Sustainability of Farming in Aegean Region (2012)
• Küresel Ekonomik Krizin Çiftçi Düzeyindeki Etkilerinin Çeşitli Yönlerden Analizi: İzmir İli Örneği (2011)
• Uluslararası Zeytinyağı Piyasasındaki Son Gelişmeler Türkiye İçin Fırsatlar (2011)
• Future Energy Consumption in Turkish Agriculture (2011)
• A co-integration analysis of the price and income elasticities of energy demand in Turkish agriculture (2011)
• Türkiye de Tarımsal İşgücü Piyasası ve Sosyal Güvenlik Politikaları (2010)
• Market dynamics in the Turkish olive oil industry (2010)
• Consumer preferences for purchase places of organic fruits andvegetables in Turkey (2010)
• Bölgesel Kalkınma Hedeflerinde Önceliklerin Belirlenmesi Tarım Sektöründe Yoğunlaşma Analizi (2010)
• The Turkish olive oil sector's priorities related to the factors affecting domestic and international competition (2010)
• Consumer preferences for purchase places of organic fruits and vegetables in Turkey (2010)
• The competitiveness of Turkish olive oil on the world market (2010)
• Competitiveness of Mediterranean Countries in the Olive Oil Market (2010)
• Türkiye de Ekonomik Krizler ve Tarıma Yansımaları (2009)
• Türkiye nin Tarım Ürünleri Dış Ticaretinin Yapısal Analizi (2009)
• Türkiye de Beyaz Et Sektörünün AB Uyum Süreci Açısından Değerlendirilmesi (2008)
• Türkiye deki Dış Ticaret Açığı Sorunu ile Tarım Ürünleri Dış Ticareti Arasındaki İlişkiler (2008)
• A Market Share Analysis of Virgin Olive Oil Producer Countries with special respect to Competitiveness (2007)
• WTO Positions of Mediterranean Countries and Potential Alliances for Turkey, CIHEAM Mediterranean Observatory, (2007)
• A market share analysis of virgin olive oil producer countries with special respect to competitiveness (2007)
• Türkiye de Enflasyon Büyüme İlişkisi Tarım Sektörü İtibariyle Ekonometrik Bir Analiz (2007)
• Türkiye de Yem Fiyatlarındaki Değişimin Broiler Fiyatlarına Etkisi (2006)
• Türkiye’de Tarım Politikalarında Değişim (2006)
• Türkiye de Zeytinyağı Sektörünün Rekabet Edebilirlik Analizi (2006)
• Tarım Ürünleri Fiyatlarına Döviz Kurunun Yansıması Pamuk Örneği (2006)
• DTÖ İleri Tarım Müzakerelerinin Türk Tarımı Açısından Değerlendirilmesi (2006)
• Dünya zeytinyağı piyasasında rekabet analizi Türkiye ve AB karşılaştırması (2006)
• . Türk Tarımına Genel Bakış (2005)
• Türk Tarımına Genel Bakış, Denizbank Tarım Bankacılığı Yayınları, (2005)
• AB de Kümes Hayvanları ve Yumurta Ortak Piyasa Düzenleri ve Türkiye nin Uyumu Açısından Değerlendirilmesi (2005)
• The agricultural dossier in the relations between Turkey and the EU (2004)
• The Situation of Agriculture, Food and The Rural Economy in Turkey (Country Report) in Development and Agri-food policies in the Mediterranean Region, CIHEAM Annual Report 2004 (Editors: B. Hervieu, M. Allaya, S. Bedrani, R. Capone, J.M. Alvarez-Coque, G. Malorgio, G. Miclet, P. Oliver), (2003)
• Development and agro-food policies Turkey 2002, CIHEAM Mediterranean Observatory, (2003)
• Türkiye Tohumculuk Dış Ticaretindeki Gelişmeler (2002)
• The Situation of Agriculture, Food and The Rural Economy in Turkey (Country Report) in Development and Agri-food policies in the Mediterranean Region, CIHEAM Annual Report 2002 (Editors: E. Chioccioli, M. Allaya, N. Akesbi, S. Bedrani, R. Capone, J.M. Alvarez-Coque, G. Malorgio, G. Miclet, P. Oliver, A. Simantov), (2002)
• Tarım Ürünlerinin Uluslararası Rekabetinin Ölçülmesi Domates Salçası Örneği (2000)
• The Situation of Agriculture, Food and The Rural Economy in Turkey (Country Report) in Development and Agri-food policies in the Mediterranean Region, CIHEAM Annual Report 1999 (Editors: E. Chioccioli, A. Di Giulio, M. Allaya, N. Akesbi, J.M. Alvarez-Coque, G. Malorgio, G. Mergos, A. Simantov), (1999)
• Avrupa ülkelerinde tarımsal üretimin verimlilik teknolojik değişme ve etkinlik değişimi açısından karşılaştırmalı analizi (1999)
• Comparative Analysis of European Countries in Terms of Productivity Technology and Efficiency Change in Agricultural Production (1999)
• Comparative analysis of European countries in terms of productivity (1999)
• The Situation of Agriculture, Food and The Rural Economy in Turkey (Country Report) in Development and Agri-food policies in the Mediterranean Region, CIHEAM Annual Report 1998 (Editors: E. Chioccioli, A. Di Giulio, A. Simantov, M. Allaya, F. Lerin, G. Mergos, G. Malorgio, J.M. Alvarez-Coque), (1998)
• The Research Network For Endogenous Development in the Mediterranean Region with Special Reference to Turkey (1998)
• OTP ndaki Reformlarla AB Tarımsal Kooperatifçiliği ndeki Gelişmeler (1998)
• Ege Bölgesi Tarımın Ulusal Ekonomideki Yeri ve Önemi (1998)
• Research Network for Endogenous Rural Development in the Mediterranean Region Country Report, CIHEAM-MAICH, (1997)
• Türkiye Ekonomisi ve Kırsal (Tarımsal Kalkınma) Uygulamaları, Basılmamış İnceleme, İzmir. (1996)

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