我國家庭糧食安全及糧食不安全脆弱性之實證分析

An Empirical Analysis on Household Food Security and Vulnerability to Food Insecurity in Taiwan

林信維(Hsin-Wei Lin)

指導教授 ： 林國慶

國立臺灣大學/生物資源暨農學院/農業經濟學研究所/博士(2018年)

https://doi.org/10.6342/NTU201810001

摘要

消除貧窮與飢餓為世界各國關注的焦點，亦是人類發展的目標之一。近二十年來我國糧食價格的成長幅度，大於平均物價的成長幅度，家庭可支配所得不均程度逐年惡化，中低收入戶戶數亦逐年增加，家庭糧食安全的狀況需要政府與大眾之關注。目前我國政府設有多項與家庭糧食安全相關之政策措施，但仍未有對我國家庭糧食安全做調查、監測與評估。因此，難以了解當前我國家庭糧食安全與我國家庭糧食不安全脆弱性。另外，根據過去之相關文獻，若沒有家庭糧食消費數量、糧食安全自我評估或飲食營養之相關資料，將難以比較不同家庭之糧食安全，也難以判斷一個家庭是否處於糧食安全之狀態。本研究將家庭糧食安全的概念與家庭糧食消費之效用連結，建立考量家庭等值規模之二次式近似理想需求體系模型，估計我國非農家庭之等值規模函數，並以等值規模函數將不同結構家庭之家庭糧食支出，轉換為家庭糧食等值支出，此亦為以貨幣衡量的家庭糧食消費效用值，代表家庭成員每人平均的糧食消費效用。透過樣本家庭糧食等值支出，推估我國非農家庭糧食等值支出母體分配，進而計算我國各類家庭糧食不安全之比例，以及模擬分析我國各類家庭糧食安全之脆弱性。由於從事農業生產的家庭通常會食用自家生產的糧食，而若在實證分析時，沒有將農家排除，則家庭糧食安全水準將會被低估，因此，本研究的研究對象限定在非農家庭。本研究之實證結果如下：（1）當家庭糧食安全門檻為35,000元、40,000元、45,000元與50,000元時，我國非農家庭糧食不安全比例分別為0.7％、2.4％、5.6％與10.9％。（2）我國於2005年及2008年至2011年間，非農家庭糧食安全水準較低，此可能與我國於2005年糧食價格急遽攀升，以及全球於2007年至2008年間發生的全球糧食危機與2008年至2009年發生的環球金融海嘯相關。（3）非農獨居老人家庭與未滿65歲之單人家庭之糧食不安全比例最高，其次為夫婦家庭、單親家庭與祖孫家庭。在我國糧食不安全之非農家庭中，核心家庭與夫婦家庭所占的比例最高。（4）若家庭糧食安全門檻為45,000元，則當糧食價格分別上漲10％與上漲20％，我國非農家庭糧食不安全比例將由5.6％，分別增加3.1％與7.6％。而若發生類似2006至2009年糧食價格危機與環球金融危機之衝擊（糧食價格上升10%，非糧食物價上升5％，家庭總支出下降1.5%），則我國非農家庭糧食不安全比例將增加4.9％左右。（5）一般而言，低收入家庭、可支配所得較低的家庭，以及未滿65歲單人家庭、單親家庭與祖孫家庭，其家庭糧食不安全脆弱性較高。（6）整體而言，非糧食價格上漲對於我國非農家庭糧食安全之衝擊較大，然而，對於低收入家庭而言，糧食價格上漲對其家庭糧食安全產生的衝擊，遠大於非糧食價格上漲或家庭總支出下降。本研究建議，政府應重視家庭糧食安全之相關研究，包括相關資料之調查與蒐集，關注國際與國內糧食價格之巨幅波動，並採取必要政策措施，以確保我國家庭之糧食安全。除此之外，目前政府社會扶助的重點族群為低收入家庭，以及中低收入之失能或獨居老人家庭，建議政府亦應多關注家庭糧食安全水準較低，且家庭糧食不安全脆弱性亦較高之未滿65歲之單人家庭、單親家庭與祖孫家庭。雖然政府針對弱勢家庭設有多項生活扶助措施，過去我國非農家庭糧食安全仍受到糧食價格危機與環球金融海嘯之衝擊而顯著惡化。為因應相關突發事件對於我國家庭糧食安全之衝擊，建議我國政府應擬定相關的緊急應變方案。最後，建議我國政府考量家庭結構對家庭每人平均福利之影響，重新審視社會救助之相關標準。

關鍵字

糧食安全 ； 家庭糧食安全 ； 脆弱性分析 ； 二次式近似理想需求體系 ； 等值規模

並列摘要

Reduction of poverty and hunger is the focus of all countries worldwide and also an important human development goal. Over the past twenty years, the growth of food prices in Taiwan has surpassed the growth of average prices. In addition, household income inequality has gradually worsened and the number of low- and mid-income households is increasing year over year, making household food security an issue of concern for the government and the public. Currently, the government has established household food security measures but has yet to survey, monitor, and assess household food insecurity in Taiwan. This makes it difficult to get a clear picture of household food security and food insecurity vulnerability conditions. In addition, past literature shows that it is difficult to compare food security conditions of different families or judge standards of food security if there is little information related to quantity of household food consumption, household food security self-assessment, or dietary nutrition. This study integrates household food security concepts with utility of household food consumption, using a household equivalence scale and the quadratic almost ideal demand system to construct an equivalent scale function of non-agricultural households; this function was used to convert inequivalent household food expenditures of different families into food equivalent money-metric utility expenditures which estimates the average food utility per capita. The household food equivalent expenditure derived from study samples was used to derive the population distribution of non-agricultural household equivalent expenditures and was further used to calculate ratios of household food insecurity in Taiwan for the purposes of analyzing food insecurity vulnerability. Agricultural households usually consume their own product and therefore household food security levels may be underestimated if agricultural households are not excluded from empirical analyses. For this reason, only non-agricultural households were considered in this study. Study results are summarized as follows: (1) At household food security thresholds of $35,000, $40,000, $45,000, and $50,000, household food insecurity ratios were 0.7%, 2.4%, 5.6%, and 10.9%, respectively. (2) Household food security levels were lower for 2005 and 2008-2011 due to a sharp rise in food prices in 2005, the global food crisis of 2007-2008, and the global financial crisis of 2008-2009. (3) Household food insecurity ratios were highest for non-agricultural elderly families and single adults; DINKY families, single-parent families, and intergenerational families showed the second highest ratios. However, nuclear and DINKY families accounted for the highest proportion of food-insecure non-agricultural families. (4) At the household food security threshold of $45,000, if food prices rise by 10% and 20%, the proportion of household food insecurity in non-agricultural households in Taiwan will increase by 3.1% and 7.6%, respectively. If affected by global food or financial crises such as those of 2006-2009, where food price rose by 10%, non-food prices by 5%, and total household expenditures fell by 1.5%, the proportion of food insecurity in non-agricultural households may increase by 4.9%. (5) In general, low-income households, families with lower disposable income, single adults, single-parent families, and intergenerational families are more vulnerable to food insecurity. (6) Overall, non-food price increases have the greatest impact on household food security for non-agricultural households. However, for low-income households, a rise in food prices impacts household food security at a much higher degree compared to a rise in non-food prices or a decline in total household expenditure. According to these results, this study recommends that the government focus on household food security research and monitoring, and track fluctuations in international and domestic food prices to establish necessary measures that ensure household food security in Taiwan. Additionally, current government social welfare policies focus on low-income households and disabled or lone seniors in mid-to-low-income households, but it is recommended that focus also be put on food-insecure households with higher levels of food security vulnerability, such as single adults, single-parent families, and inter-generational families. Although many social welfare measures have been established for vulnerable families, non-agricultural households are still suffering from the impacts of past global food and financial crises and food security levels continue to deteriorate. The government should draw up relevant response plans to cope with emergency impacts on household food security. Finally, this study recommends that the government re-examine standards for social welfare based on the impacts of family structure on average per capita utility.

並列關鍵字

Food Security ； Household Food Security ； Vulnerability Analysis ； Quadratic Almost Ideal Demand System ； Equivalence Scale

參考文獻

王金利、李庸三，1987。「等值規模與台灣家計消費型態：民國73 年家庭收支調查樣本之計量分析」，『台灣經濟預測』。18卷，2期。45-82。

王瑞蓮、蕭寧馨，2003。「台灣營養調查 NAHSIT I 1993~1996之飲食多樣性與其對營養充足程度的影響」，『臺灣營養學會雜誌』。28卷2期。52-64。

台北市政府社會局，2018。『失能老人營養餐飲服務』。台北：台北市政府社會局。取自https://dosw.gov.taipei/News_Content.aspx?n=73E6C19BCAB3CBEE&sms=D93B3E44DF866BC7&s=87FE55991460A56A

行政院主計總處，2009a-2017a。『物價統計月報』。台北：行政院主計總處。取自https://www.dgbas.gov.tw/lp.asp?CtNode=3091&CtUnit=333&BaseDSD=7&mp=1

行政院主計總處，2003b-2017b。『家庭收支調查原始檔』。台北：行政院主計總處。