Food security measurement in a global context: The Food Insecurity Experience...
Food security measurement in a global context: The Food Insecurity Experience Scale全球范围内的粮食安全测量:粮食不安全经验量表
The ability of households and individuals to access food (one of the key aspects of 'food security') is an
important welfare dimension that poses important challenges for objective measurement. This paper describes
the Rasch model-based procedures developed to define the eight-item Food Insecurity Experience Scale (FIES)
as a contribution towards the establishment of an indicator for global monitoring of food insecurity.
Experiential food insecurity survey data, collected by FAO from nationally representative samples of the adult
population, once every year in 2014, 2015 and 2016 from 153 countries or territories, are used to develop
methods to estimate cross-country comparable prevalence rates of moderate and severe food insecurity. A Rasch
model-based scale was estimated separately for each country and data were assessed for consistency with model
assumptions. To ensure cross-country comparability, a procedure based on the median normalized severities of
each of the eight FIES items was used to define a global reference scale, against which measures obtained in each
country can be separately calibrated. Calibration is obtained by equating the mean and standard deviation of the
severity parameters of the items that appear to be common between the national and the reference scale, and
thus used as anchoring points for the metric. Data showed sufficient consistency with the Rasch model
assumptions to produce reliable measures of the prevalence of food insecurity in each country. Calibration was
possible using 4 or more items as anchoring points in 151 of 153 (98.7%) of the cases, and 6 or more items in the
vast majority of them (121 cases). Concurrent validation of the estimates of prevalence of food insecurity at
national level was obtained by comparing the FIES-based indicator with other established indicators of social
(under)development. National prevalence rates of moderate-or-severe food insecurity obtained by FAO
correlate well with the prevalence of undernourishment and with several widely used indicators of national
income, health, and well-being. The proposed calibration method can be applied to other existing experiencebased
food security scales that use similar items, thus affording the possibility to use data collected with those
instruments to produce internationally comparable measures of the prevalence of food insecurity. Pending
broader adoption of the FIES or compatible experience-based food security scales worldwide, countries could
choose to use the 2014-2016 results obtained using the data collected by FAO as the baseline to monitor progress
towards Target 2.1 of the recently established 2030 Agenda for Sustainable Development.
家庭和个人获得粮食的能力(“粮食安全”的关键方面之一)是一个重要的福利方面,对客观衡量提出了重要的挑战。本文描述了基于Rasch模型的程序,该程序定义了8项食品不安全经验量表(FIES),有助于建立全球监测食品不安全的指标。粮农组织于2014年、2015年和2016年每年从153个国家或地区的具有全国代表性的成年人样本中收集一次经验食品不安全调查数据,用于制定评估中度和严重食品不安全的跨国可比患病率的方法。对每个国家分别估计了基于Rasch模型的比例尺,并评估了数据与模型假设的一致性。为确保跨国可比性,采用了一种基于8个外商投资企业项目中每一项标准化程度的中位数的程序来定义一种全球参考比例尺,根据该比例尺,每个国家获得的措施可以单独校准。校准是通过相等的平均值和标准偏差的严重程度参数的项目,似乎是国家和参考尺度之间的共同,并因此使用为度量的锚点。数据显示,这与Rasch模型的假设有足够的一致性,可以得出各国粮食不安全程度的可靠衡量标准。153例中有151例(98.7%)使用4个或以上的项目作为定位点,绝大多数(121例)使用6个或以上的项目作为定位点可以进行校正。同时对国家一级的粮食不安全程度估计进行验证的方法是将基于国际粮食安全评估的指标与其他已建立的社会发展指标进行比较。粮农组织得出的国家中度或严重粮食不安全的流行率与营养不良的流行率以及几个广泛使用的国民收入、健康和福祉指标密切相关。拟议的校准方法可应用于其他使用类似项目的现有基于经验的粮食安全量表,从而提供了利用这些仪器收集的数据来产生国际上可比较的粮食不安全程度衡量标准的可能性。在全球范围内广泛采用外商投资企业或兼容的基于经验的粮食安全尺度之前,各国可以选择使用粮农组织收集的数据获得的2014-2016年结果作为基准,监测在实现最近制定的《2030年可持续发展议程》目标2.1方面的进展情况。
Keywords – Food security measurement, Rasch model, Scale equating, Sustainable Development Goals.
关键词:粮食安全测量,Rasch模型,规模等同,可持续发展目标。
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