【美国科罗拉多州立大学论文】转基因食品标识

Labeling of Genetically Modified Foods

 

by P. Byrne, D. Pendell, & G. Graff*

 

Quick Facts...

·  Mandatory labeling of genetically modified (GM) foods has been proposed under a variety of initiatives at national and state levels but has not yet been implemented in the United States.

·  Current U.S. law mandates food labeling when there is a substantial difference in the nutritional or safety characteristics of a new food. The U.S. Food and Drug Administration (FDA) does not consider the method of genetic engineering by itself to create such a difference.

·  Companies may voluntarily label foods produced without genetic modification, and foods labeled USDA Organic are produced without genetic modification.

Whether or not to require labeling of food produced from crops that are genetically modified (GM) using recombinant DNA technology is a key issue in the ongoing debate over the risks and benefits of using biotechnology in agriculture. The U.S. government regulates GM food technologies, but once GM crops are approved they are considered to be 'substantially equivalent' to their conventional counterparts in terms of safety. Therefore, there is no federal requirement for labeling food that contains GM ingredients. Bills and ballot initiatives requiring mandatory labeling have been introduced and voted on in several states. The first states to have approved some form of mandatory labeling are Connecticut, Maine, and Vermont. Under U.S. law, companies may voluntarily label food products to inform consumers as to whether they do or do not contain ingredients from GM crops.

 

Genetically modified crops have been produced commercially and consumed in the U.S. since the mid-1990s. Today, the most common GM crops on the market are soybean, corn, cotton, canola, and sugar beet. (See CSU Extension Fact Sheet no. 0.710: Genetically Modified (GM) Crops: Techniques and Applications for more details.) Because many processed food products contain ingredients from one of these crops (e.g., soy protein or high fructose corn syrup), it is likely that a majority of processed foods in grocery stores include at least one GM crop ingredient (Lesser, 2013).

 

Current Labeling Policy

Since 1992, the U.S. Food and Drug Administration (FDA) has required labeling of GM foods only if the food has a nutritional or food safety property that is significantly different from what consumers would expect of that food. For example, if a new GM food includes a protein that may be an allergen not expected to be present (such as a peanut protein expressed in a soybean), then it would have to be labeled. Otherwise, the FDA has not considered the methods used to produce new plant varieties (such as hybridization or genetic engineering) to present systematic differences in nutritional properties or safety concerns compared to standard methods of traditional plant breeding. Therefore, the method of development is not considered material information required to be disclosed in the labeling of foods under U.S. food safety laws (FDA, 1992). Early in 2001, the FDA proposed voluntary guidelines for companies that choose to label foods as to whether they do or do not contain GM ingredients if they see sufficient market opportunities for doing so (See FDA, 2001).

 

Voluntary vs. Mandatory Labeling

There are important differences between voluntary labeling and mandatory labeling.

 

A number of companies and initiatives already voluntarily provide labeling of food products regarding their avoidance of GM ingredients. Voluntary labeling does not require further regulatory measures. The costs associated with verification that the food product does or does not use GM ingredients are only incurred by those consumers who choose to purchase the labeled product.

 

Mandatory labeling would extend much further and would require, at a minimum, that all food products containing any GM ingredient (above a certain threshold for trace amounts) to indicate that fact. Stronger mandatory labeling requirements could include identification of each specific GM ingredient and its level of content in the product. Mandatory labeling requires further regulatory interventions including monitoring and enforcement. Under a mandatory labeling system, all consumers—both those that are concerned about the GM ingredients and those that are not—help bear the costs associated with being able to verify that foods do or do not use GM ingredients.

 

The USDA Organic Label Means That a Product Is Not Genetically Modified

USDA organic standards exclude the use of genetic engineering, but do not rule out the use of more conventional breeding methods, such as hybridization or tissue culture. Organic certification depends upon reasonable precautions being undertaken to prevent commingling and contact with GM products. Therefore, products labeled as 'USDA Organic' are effectively labeled as not containing GM ingredients.

 

Pros and Cons of Mandatory Labeling

There are many arguments both for and against the mandatory labeling of GM foods. These arguments are summarized below.

 

Arguments Made in Support of Mandatory Labeling (Benefits)

Consumers have a right to know what is in their food, especially concerning ingredients for which there may be health and environmental concerns (Raab and Grobe, 2003; NRC 2010).

Mandatory labeling will allow consumers to identify and steer clear of types of food products that they wish to avoid.

For religious or ethical reasons, some Americans may want to avoid eating certain products that may be introduced by GM methods.

Voluntary labeling has not been sufficient for informing consumers about the presence of GM ingredients.

Surveys indicate that a majority of Americans support mandatory labeling.

At least 64 countries have established some form of mandatory labeling (CAST, 2014).

Arguments Made Against Mandatory Labeling (Drawbacks)

Labels on GM foods imply a warning about health effects, whereas no verifiable differences in health effects between GM and conventional foods have been detected (Domingo and Bordonaba, 2011; Nicolia et al., 2013).

If a nutritional difference or allergenic characteristic were found in a GM food, current FDA regulations already require a label to that effect.

Costs associated with labeling of GM foods would be borne broadly by most consumers in order to fulfill the desires of some consumers.

Consumers who want to buy non-GM food already have options: to purchase verified non-GM foods or certified organic foods.

Experience with mandatory labeling in the European Union, Japan, and New Zealand has not resulted in greater consumer choice. Rather, retailers have eliminated GM products from their shelves due to perceived consumer aversion to GM products (Carter and Gruere, 2003)

The food system infrastructure (storage, processing, and transportation facilities) in this country could not currently accommodate the need for segregation of GM and non-GM products.

Issues to Consider with Mandatory Labeling

Although mandatory labeling of GM ingredients may appear to be a straightforward measure, there are several complex issues that need resolving prior to implementation.

 

What percentage of a GM ingredient must be present in a food before a label is required?

For practical reasons, it is necessary to specify the threshold level of GM content allowed before the product must be labeled as GM. A commonly proposed threshold level is one percent. This is the labeling threshold decided upon by Australia and New Zealand. The European Union has decided on a level of 0.9 percent, while Japan has specified a five percent threshold. The lower the threshold, generally, the higher the cost of compliance and the broader the impact on the current food system.

 

Would meat, eggs, and dairy products from animals fed GM feed crops require a label?

Some labeling proposals include these products among those that would require labels. However, the biological rationale for doing so has not been demonstrated, that is, DNA or protein from inserted genes have not been found in livestock products. Neither the 2013 California state ballot initiative, the 2013 Washington state proposition, nor the 2014 Colorado state proposition has attempted to include meat and dairy products from animals fed GM feed grains.

 

Would food ingredients made using GM yeast or GM enzymes require a label?

Rennet, used in making cheese, and a number of other food ingredients such as some DHA (omega-3) supplements, vitamins, and lactase enzyme (added to milk for those who are lactose intolerant) are manufactured using GM algae or other GM microbes. The underlying genetic techniques used to make these are similar to those used to make GM crops. However, in the 2014 Colorado labeling proposition, for example, such foods are exempted from the labeling requirement.

 

Would food served in restaurants or other food-service establishments require a label?

In most labeling proposals that have been advanced or approved, foods sold via food service and restaurants are excluded.

 

How should regulators verify claims that a food is or is not genetically modified?

 

There are two ways that verification can be done: content based and process based verification.

 

·  Content-based verification requires testing foods for the physical presence of foreign DNA or protein. A current application of this type of procedure is the analysis and labeling of vitamin content of foods.

·  Process-based verification entails detailed record-keeping of seed source, field location, harvest, transport, and storage. This is similar to the type of 'identity preservation' system used to certify shade-grown coffee or organic foods.

 

What if just one state or a few states required labeling?

Practical issues would arise if just one or a few states required labeling while most others did not. Many food manufacturers produce for the larger regional, national, or even North American market. If requirements varied in one or a few states, that would mean manufacturers would have to produce a uniquely labeled (and possible uniquely formulated) product for sale in those states. Or they would simply label their entire product run, for all states, in compliance with strictest state's requirement. Under such conditions, one outcome might be that the Federal government would intervene, for example, on grounds that differences in state-by-state labeling requirements affect interstate commerce (see CAST, 2014).

 

What is the economic impact of mandatory labeling?

 

The cost of labeling involves more than the paper and ink to print an actual label. Costs arise from establishing and maintaining a system to track ingredients, from monitoring and enforcement or compliance with the law, from trade impacts, and from other factors. However, the impacts on producers, retailers, and consumers are likely to be varied, resulting in a net benefit to some while imposing a net cost on others.

 

Impacts along the value chain: Full and accurate labeling of specific ingredients may require an extensive identity preservation (IP) system from farmer, to elevator, to grain processor, to food manufacturer, to retailer (Maltsbarger and Kalaitzandonakes, 2000; Auer, 2003). Either testing or detailed record-keeping needs to be done at steps all along the value chain, or it would not be possible to know what specific ingredients are contained in a final food product. Other options could be less costly, such as using more general labeling language that does not require an extensive IP system.

 

In addition to these direct costs, there are also indirect costs. Food manufacturers and retailers may choose to avoid foods containing GM ingredients, requiring new formulations and sourcing arrangements. With a significant shift in demand away from GM crops, farmers would have to shift to potentially higher cost production and pest control methods.

 

Public costs for monitoring and enforcement: Costs would be borne by taxpayers to pay for agricultural and food authorities to monitor and enforce compliance with labeling requirements. These could vary significantly depending upon the terms and conditions of the requirements that are imposed.

 

Trade impacts: Another form of impact would be on trade in agricultural products. Imported products would have to comply with labeling requirements. This might effectively prevent some products from being imported and sold if the supplier of the product is unable to verify the origin of all of their contents. On the other hand, producers with verifiable labeled non-GM food products might find new export options to those countries that have comparable requirements.

 

Impacts on consumers: It is almost certain that food prices would increase to some extent as costs increase due to a labeling requirement. Estimates of the costs of mandatory labeling vary from a few dollars per person per year up to $400 per year or 10 percent of a consumer’s food bill (Gruere and Rao, 2007; Alston and Sumner, 2012; Lesser, 2014). These higher prices would be borne by all consumers, but especially by lower-income consumers, who devote a higher share of household income to food purchases.

 

Colorado Consumer Attitudes Toward GM Foods

Researchers in Colorado State University’s Department of Agricultural and Resource Economics have undertaken surveys to understand Colorado consumers' attitudes toward food attributes, including GM foods and GM labeling. In a series of surveys taken in 2001, 2006, and 2011, about one third of Colorado respondents consistently expressed the opinion that GM foods are almost always or usually safe. About a fifth of respondents expressed the opinion that GM foods are almost never safe. However, almost half of respondents expressed some degree of uncertainty, either considering GM foods sometimes safe or saying they don’t know enough to respond (Thilmany McFadden et al 2012). An earlier study found that, while 78 percent of Colorado respondents supported mandatory labeling of GM foods, they were not, however, willing to pay a premium for such labeling. Women appeared to favor mandatory labeling more than men, younger consumers were less likely to support mandatory labeling, and those who considered themselves better informed about biotechnology were less concerned that GM foods be labeled (Loureiro and Hine, 2004).

 

References

Alston, J. M., and D. A. Sumner (2012) Proposition 37–California food labeling initiative: economic implications for farmers and the food industry if the proposed initiative were adopted. A paper written for the ‘No on 37’ campaign, September 3, 2012, www.noprop37.com/wp-content/uploads/2014/09/Alston-Sumner-Prop-37-review.pdf.

Auer, C.A.,Tracking genes from seed to supermarket: techniques and trends. Trends in Plant Science, (2003) 8: 591-597.

Carter, C.A., and Gruere, G.P., Mandatory labeling of genetically modified foods: Does it really provide consumer choice? AgBioForum, 2003, 6(18), www.agbioforum.org/.

Council for Agricultural Scuence and Technology (CAST), The Potential Impacts of Mandatory Labeling for Genetically Engineered Food in the United States. 2001, Issue Paper 54. Council for Agricultural Science and Technology (CAST), Ames, Iowa.

Domingo, J. L., and Bordonaba, J. G., A literature review on the safety assessment of genetically modified plants. Environment International, (2011), 37(4): 734-742.

Food and Drug Administration, Statement of policy: foods derived from new plant varieties, Federal Register, Vol. 57, No. 104, U.S. Food and Drug Administration, Friday, May 29, 1992 (see part VI. Labeling) www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/Biotechnology/ucm096095.htm

Food and Drug Administration, Draft guidance for industry: voluntary labeling indicating whether foods have or have not been developed using bioengineering, Draft released for comment January 2001. U.S. Food and Drug Administration. www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/ucm059098.htm

Gruere, G.P., and Rao, S.R., A review of international labeling policies of genetically modified food to evaluate India’s proposed rule. AgBioForum, 2007, 10, 1, www.agbioforum.org/.

Lesser, W., Costs of labeling genetically modified food products in N.Y. state, 2014, Dyson School of Applied Economics and Management, Cornell University, http://dyson.cornell.edu/people/profiles/docs/LabelingNY.pdf

Loureiro, M.L., and Hine, S., Preferences and willingness to pay for GM labeling policies. Food Policy, 2004, 29: 467–483.

Maltsbarger, R., and Kalaitzandonakes, N., Direct and hidden costs in identity preserved supply chains. 2000, AgBioForum, 3(4), www.agbioforum.org/.

National Research Council (NRC), Impact of Genetically Engineered Crops on Farm Sustainability in the United States. 2010, The National Academies Press, Washington, DC.

Additional Information

AgBioForum (www.agbioforum.org) 2000, Vol. 3, No. 4, issue is devoted to labeling of food produced through biotechnology.

The Center for Food Safety, www.centerforfoodsafety.org, leads a campaign in favor of mandatory labeling.

Consumer Union, www.consumerunion.org, advocates a number of food safety issue including improved regulation and labeling of GM foods.

* P. Byrne, Colorado State University Extension agronomy specialist and professor, soil and crop sciences; D. Pendell, associate professor, agricultural and resource economics; and G. Graff. associate professor, agricultural and resource economics. 10/2014

 

Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

 

Updated Tuesday, November 25, 2014

转基因食品标识

P. Byrne，D. Pendell，G. Graff

2014年10月25日

 

P. Byrne, 科罗拉多州立大学推广农学专家、教授，作物与土壤学；

D. Pendell, 助理教授, 农业和资源经济学；

G. Graff，助理教授, 农业和资源经济学。

科罗拉多州立大学，美国农业部和科罗拉多州合作的CSU发展项目向所有人公开，本文亦未有意肯定文中提到的产品，也未批评没有提到的产品。

 

快讯：

l   转基因食品(GM)强制标识在全国及各州层面的多项活动中早已提倡实施，但至今并未在美国实施。

l   当新种类食物在营养性及安全性方面有本质性差异时，美国当前法律规定需食品标识。美国食品药品管理局（USDA）并不考虑通过转基因工程方法造成食品在营养性及安全性方面的差异。

l   食品公司可能自愿标识非转基因食品及USDA认可的有机非转基因食品。

 

在农业中使用生物技术的风险和利益争论中，其关键问题是：是否需要对通过使用DNA 重组技术的转基因农作物食品进行标识？美国政府控制转基因食品技术，但是一旦转基因作物获得批准，消费者将认为转基因作物和传统的作物在安全方面是“实质相同”的。因此，政府对含有转基因成分的食品并未做统一要求。少数个别州要求强制标识的立法案和选举方案已被提出和表决。率先批准强制性标识方案的州包括：康乃迪克州，缅因州，和佛蒙特州。美国法制下，食品公司也许会自发地标识转基因食品以告知消费者，从而让其对转基因食品有自主选择权。

自20世纪90年代中期，转基因作物在美国已实现商业化并出现在市场上。现在，市场上最常见的转基因作物是大豆、玉米、棉花、油菜和甜菜（详见CSU 发展项目简报第.0.710期: 转基因作物：技术与应用）。因为很多已加工食品的原料成分中含有转基因成分（例如：大豆蛋白或者高果糖浆），因此食品店里大部分食品至少含有一种转基因作物成分（Lesser, 2013）。

现行标识政策

自1992年起，只要食品的营养和安全跟消费者需要的食品有了显著差异，美国食品药品管理局（FDA）就要求对转基因食品标识。例如，假如转基因食品中含有非预期出现的过敏原（如，将花生蛋白放入大豆中），那么就必须标识该类食品。否则，美国食品药品管理局（FDA）并不会认为培育新型作物品种的方法，与传统植物育种的标准方法相比，在营养属性或者安全方面存在着系统性差异。因此，在美国食品安全法框架下（FDA，1992），培育方式并不是披露食品标识所需要的重要信息。2001年早期，美国食品药品管理局（FDA）提出：企业标识食品坚持自愿性原则，依据市场机会决定是否标识含有转基因成分的食品。（参见FDA，2001）。

自愿性VS.强制性标识

自愿性和强制性标识在这里有着重要的区别。

大量的企业提倡自愿地开展食品标识以规避转基因食品。自愿性标识不需要进一步的规范措施。关于核实食品是否含有转基因成分所需成本仅来自于那些选择购买标识食品的消费者。

强制性标识则需进一步规范措施，要求所有含转基因成分的食品对此进行标识。更加严格的强制性标识要求标识食品中含有的具体转基因成分及含量。强制性标识需要进一步加强监管干预措施，包括监管和强制执行。在强制性标识系统下，无论是否在意转基因食品，所有消费者均承担了核实食品中是否含有转基因成分所需费用。

美国食品药品管理局（USDA ）的有机标识表明食品为非转基因食品

美国食品药品管理局（USDA）的有机标准拒绝使用基因技术，但不是反对使用更多的传统育种方式，比如杂交和组织培养。有机认证是依赖于采取合理的预防措施来防止杂交及相关的转基因食品。因此，类似于“美国食品药品管理局有机认证”的食品标识有效地表明了该食品不含有转基因成分。

强制性标识的利弊

关于是否进行转基因食品强制性标识争议很大，概括有以下几点。

支持食品强制性标识的观点（利）：

l   消费者有权利了解他们所食用食品中含有成分，尤其关注可能影响健康和环境的成分(Raab and Grobe, 2003; NRC 2010)。

l   强制性标识会让消费者识别和避开他们不想要的食品。

l   由于宗教或道德原因，很多美国人也许想要避免食用某些转基因食品。

l   自愿性标识并不能将食品中转基因成分完整地告知消费者。

l   调查结果表明大部分美国人支持强制性标识。

l   至少64个国家已经建立强制性标识体系（CAST, 2014）。

反对食品强制性标识的观点（弊）

l   转基因食品标识是潜在提醒消费者其对健康的影响，然而并没有证实转基因食品和传统食品对健康的影响差异(Domingo and Bordonaba, 2011; Nicolia et al., 2013)。

l   如果在转基因食品中发现具有营养性差异或者过敏性特点，那么美国食品药品管理局条例早已要求对此类影响进行标识。

l   为满足一些消费者需求，标识转基因食品产生的相关费用需由大部分消费者来承担。

l   想购买非转基因食品的消费者已经有了选择：购买已认证的非转基因食品或有机认证食品。

l   欧盟、日本和新西兰实施强制性标识措施的实践经验表明此举并未给予消费者更多的选择。相反，由于认为消费者反感转基因食品，零售商禁止转基因食品出现在他们的货架上（Carter and Gruere, 2003）。

l   美国当前食品系统基础设施(存储、加工、运输设施)尚不能满足区分转基因食品和非转基因食品的要求。

强制性标识需要考虑的问题

尽管强制性标识转基因食品看起来更像是一种直接可实施的措施，但在实施前仍需解决一些复杂的问题。

在标识之前，需确定食品中转基因成分占有比例是多少？

由于操作性原因，在标识转基因食品之前，需先规定转基因食品中允许包含转基因成分比重的门槛标准。通常建议门槛标准设为1%，这是澳大利亚和新西兰制定的标识门槛。欧盟已经确定为0.9%，而日本规定了5%的标准。一般来说，门槛越低，实施成本就越高，对现行的食品体系影响也就越广泛。

产于喂食转基因饲料作物牲畜的肉类、鸡蛋和乳制品需要标识吗？

一些提议中提到将该类食品进行标识，但是生物学原理还没有证实这样的做的合理性，换而言之，在畜产品中没有发现来自于外来植入基因的DNA或者蛋白质。2013年加利福尼亚州公民投票表决，2013年华盛顿州提议案，以及2014年科罗拉多州提议案都没有提出尝试标识产于喂食转基因饲料谷物牲畜的肉类和乳制品肉类和乳制品。

使用含有转基因酵母或者转基因酶的食品添加剂需要标识吗？

用于生产奶酪的凝乳酵素和大量其他的食品添加剂，比如DHA(欧米伽-3)补充剂、维他命和乳糖酵素，是使用转基因蓝藻或者转基因微生物加工出来的。用于制造这些添加剂的基因技术跟那些生产转基因作物的技术相类似。然而，在2014年科罗拉多标识提案中，此类食物却被免于标识。

饭店里的食品和其他食品服务机构的食品需要标识吗？

在大多数提出或批准的标识提案中，排除了食品服务和饭店出售的食品。

监管者如何证实食品是否为转基因？

•   有两种证实方法：以含有成分为基础和以加工为基础。

•   以含有成分为基础的证实方法要求检测食品中外源DNA或蛋白质的物理存在。现有的这类程序申请是分析和标识食品中的维生素成分。

•   以加工为基础的证实方法须要对种子来源、田地位置、收割、运输和存储有详细的记录。这类似于用来证明在树荫下成长的咖啡或有机食品“身份追溯”系统。

若只有一个或几个州要求标识怎么办？

若只有一个或几个州要求标识而其他大多数州不要求，实际问题就会出现。许多食品生产者是为较大的地区、国家甚至北美市场服务的。如果一个或几个州有不同的要求，就意味着生产者为了能够在那些州销售产品，不得不生产具有独特标识（和可能独特配方）的产品。否则他们只需在达到标准最严格州的要求前提下，在所有产品上做统一的、放之全国皆可的标识即可。在这样的条件下，一个可能的结果是联邦政府将会出面干涉，比如，由于各州对标识的要求不同影响到了州际贸易（参照CAST,2014）。

强制标识的经济影响是什么？

标识的成本远不止印刷标签的油墨费，还包括：为了追踪食品成分而建立和维护该系统花费成本，监管以及实施法律花费成本，贸易影响产生的成本，以及其他因素产生的成本。然而，强制标识对生产者、销售者和消费者的影响可能会不同，有些人获利，而有些人则增加成本。

对产业链的影响：对某些成分全面和准确的标识可能需要对大范围农民进行身份追溯（IP）系统，涉及到运输，粮食生产，食品加工，和销售等各个环节（Maltsbarger and Kalaitzandonakes, 2000; Auer, 2003）。必须对整个产业链的每一个环节进行检测或详细记录，否则不可能知道在最终面向消费者的食品中包含了什么成分。其他的办法可能成本相对少，比如使用不需要大范围身份追溯系统的更通识的标识语言。

除了以上直接成本，还有间接成本。食品生产者和销售者可以选择不含转基因成分的食品，需要新的配方和采购安排。对转基因作物的需求大大改变后，农民们可能不得不转向潜在成本更高的产品和控制虫害的方法。

公众监管和实施成本：根据标识需要而实行的农业和食品机构的监测和实施将会由纳税人来买单，这些成本可能会根据标识要求条件的不同而大相径庭。

贸易影响：另一个影响是对农产品交易的影响。进口产品必须符合标识要求。如果提供商不能证实食品中所有成分的来源，这可能会有效地防止一些产品的进口和销售；而另一方面，生产可证实的非转基因食品生产者可能会寻求新的出口办法，出口到那些有可比性要求的国家。

对消费者的影响：由于食品标识成本增加，食品价格一定程度上涨几乎是必然的。对强制标识成本的估算由每人每年几美元上至每年400美元或占到消费者食物总消费的10%(Gruere and Rao, 2007; Alston and Sumner, 2012; Lesser, 2014)。这些高出的价格都会由消费者来承担，尤其是那些在食品上花费比例较高的低收入消费者。

科罗拉多消费者对转基因食品的态度

为了解科罗拉多消费者对食品特性的态度，包括对转基因食品和转基因标识的态度，科罗拉多州立大学农业与资源经济学院的研究者们特对此做了调查。在2001年、2006年以及2011年做的一系列调查中，大约三分之一的科罗拉多人一致认为转基因食品几乎是或通常是安全的；大约五分之一的人认为转基因食品永远不可能安全；几乎一半的人持怀疑态度，要么认为转基因食品有时候是安全的，要么说他们也不太了解(Thilmany McFadden et al 2012)。早期一项研究发现，尽管78％的科罗拉多人支持转基因食品的强制标识，但他们不愿为之支付额外的费用。女士们似乎比男士更倾向于强制标识，年轻的消费者相对不太支持，认为自身了解生物技术的人不太关心转基因食品标识(Loureiro and Hine, 2004)。

参考文献

•      Alston, J. M., and D. A. Sumner (2012) 37号议案–加州食品标识倡议：议案被采纳后对农民和食品产业的经济意义。一篇为“反对37号议案”而写的文章，2012年9月3日，www.noprop37.com/wp-content/uploads/2014/09/Alston-Sumner-Prop-37-review.pdf.

•      Auer, C.A.，基因追踪，从种子到超市：技术和趋势。植物科学趋势，(2003) 8: 591-597。

•      Carter, C.A., and Gruere, G.P.,转基因食品的强制标识：真的给了消费者一个选择吗？农业生物论坛, 2003, 6(18), www.agbioforum.org/。

•      农业科学和技术委员会(CAST)，美国转基因食品强制标识的潜在影响，2001，出版论文54。农业科学和技术委员会，艾姆斯，洛瓦。

•      Domingo, J. L., and Bordonaba, J. G.,转基因植物的安全评估文献综述。全球环境, (2011), 37(4): 734-742.

•      食品药品监督局，政策陈述：从新植物品种中衍生的食品，联邦纪事，57卷，104号，美国食品药品监督局，1992年5月29日，周五 (参照第6部分，标识)www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/Biotechnology/ucm096095.htm

•      食品药品监督局，产业指南草案：说明食品是否使用生物工程的自愿标识，草案公布以供评价，2001年1月，美国食品药品监督局。www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/ucm059098.htm

•      Gruere, G.P., and Rao, S.R., 综述国际转基因食品标识政策以评价印度提案规则。农业生物论坛，2007, 10, 1, www.agbioforum.org/.

•      Lesser, W., 纽约州的转基因食品标识成本，2014, 康奈尔大学戴森学院应用经济与管理 http://dyson.cornell.edu/people/profiles/docs/LabelingNY.pdf

•      Loureiro, M.L., and Hine, S., 为转基因标识政策买单的偏好和意愿。视频政策，2004， 29: 467–483.

•      Maltsbarger, R., and Kalaitzandonakes, N., 身份保存供应链的直接和隐藏成本。2000年，农业生物论坛，3(4), www.agbioforum.org/.

•      国家调查委员会(NRC), 转基因作物对美国农场可持续性的影响。2010年，国家学术出版社，华盛顿。

•      附加信息

•      农业生物论坛 (www.agbioforum.org) 2000, 卷 3, 第4号, 为生物技术食品标识专门开设板块。

•      食品安全中心, www.centerforfoodsafety.org, 领导了支持强制标识的一个组织.

•      消费者联合, www.consumerunion.org,主张许多食品安全问题包括转基因食品规范和标识。