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Janet Carpenter

Owner, J E Carpenter Consulting LLC M.S. Agricultural and Resource Economics

Expert Bio

I have been working on understanding the reasons farmers worldwide are adopting GMO crops and estimating the impacts of GMO crop technology for 15 years, starting in the late 1990s when we were witnessing high adoption rates for insect-resistant corn and cotton and herbicide-tolerant soybeans in the U.S. and other countries. At this point, the accumulated evidence on the impacts and safety of GMO crops is extensive. I have enjoyed reviewing this body of evidence in my most recent work, addressing direct economic impacts, impacts on biodiversity and the broad socioeconomic impacts of currently commercialized technology globally.

Studies, Articles and Answers

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Q: Since all stages of GMO conventional agriculture heavily rely on petroleum, how will this affect the price of food and environmental pollution in the long term? If we were to fully embrace GMO conventional wouldn't we be depending dangerously on a raw m

Answered By Janet Carpenter - Jan 30, 2014

A: The facts do not support the idea that GM crops are more heavily reliant on petroleum than conventional or organic crops. One of the largest uses of petroleum in agriculture is for running machinery across fields to mechanically control weeds through tillage operations. Prior to the introduction of GM herbicide-tolerant crops, farmers were already adopting reduced tillage practices, which were made possible with the availability of selective postemergent herbicides that could be used on growing weeds without harming the crop. Since the introduction of GM crops, many studies have shown that th [...]

Environment Health & Safety


Q: If consumer opposition to GMO products is so strong, why not stick to making Non-GMO seeds better through breeding? A June 2013 study published in the International Journal of Agricultural Sustainability entitled "Sustainability and innovation in staple c

Answered By Janet Carpenter - Dec 05, 2013

A: While the yield benefits of currently commercialized GM crops in developed countries such as the U.S. may not be large, surveys of farmers in both developed and developing countries show that GM crop farmers in developing countries have achieved much greater yield increases.  Currently commercialized technologies are intended to improve pest management and therefore reduce or eliminate losses for insect damage or weed competition.  In developed countries, these technologies have substituted for other pest-management practices and have been adopted for reasons other than yield i [...]

GMO Basics How GMOs Are Made


Q: Regarding sustainability, I was hoping you could address the findings in the research study conducted by Canterbury University Professor Jack Heinemann, based on an analysis of data on agricultural productivity in north America and Western Europe over the

Answered By Janet Carpenter - Jan 17, 2014

A: I would encourage a critical read of the paper that you reference, as the conclusions are not based on any careful analysis of the similarities and differences between North American and European production systems.  As I indicated in a response to an earlier question about the Heinemann paper, I believe the authors’ “conclusions” are better characterized as assertions.  First of all, it is important to recognize the multitude of factors that influence yields and pesticide use, such as climate, soils, farming practices, government subsidies and subspecies of the crop grown (which is [...]

Environment Crop protectants


Q: What is a consumer to believe about increased yields from GMO crops when the industry claims they have increased yields and other sources claim they haven't? Is there any evidence that is totally outside of industry control that backs up the industry's c

Answered By Janet Carpenter - Sep 12, 2013

A: The impact that GMO crops have had on yields is dependent on several factors.  The first wave of GMO crops to be commercialized has embodied traits intended to improve pest management and therefore reduce or eliminate losses from insect damage or weed competition.  These technologies do not raise yield potential, but they can improve yields substantially, especially where conventional insect- and weed-management control technologies are limited in their effectiveness or availability.  For example, conventional insecticides may become ineffective as a result of their overuse and [...]

Business Practices GMOs & Farmers


Q: How many pounds of GM foods are produced each year in the U.S.A.

Answered By Janet Carpenter - May 08, 2014

A: The answer to this seemingly straightforward question is, unfortunately, not so simple. However, when we look across the eight crops for which GM varieties are currently grown commercially in the U.S. (corn, soybeans, cotton, sugar beets, canola, alfalfa, squash and papaya), most of them are used for animal feed, biofuel, textiles or other industrial uses, not directly for food. Of the food uses, most of the GM food reaches grocery store shelves in the form of processed products. Currently, there is very little GM food in the U.S. that is consumed as unprocessed whole food. The uses of each o [...]

By GMOAnswers Admin_1 - May 08, 2014

How many pounds of GM foods are produced each year in the U.S.A. [...] [...]



Q: In 2009, the Union of Concerned Scientists UCS published a report titled Failure to Yield, available for download at httpwww.ucsusa.orgfoodandagricultureourfailingfoodsystemgeneticengineeringfailuretoyield.html. Are the reports conclusions that GM has la

By Community Manager - Oct 01, 2014

A: The Union of Concerned Scientists (UCS) was correct in pointing out the success of modern plant breeding and the need for multiple crop-production tools. Yet the UCS has taken a very narrow view of the promise of genetically engineered or genetically modified (GM) crops.   American farmers are not only some of the most productive in the world but also among the most efficient users of irrigation water, fertilizer and other inputs, and among the lowest contributors of GHG emissions (Grassini and Cassman, 2013; West et al., 2014; Chen et al., 2014). GM crops are an important part of t [...]

Answered By Janet Carpenter - Sep 04, 2014

A: The UCS report that you mention draws overarching and mistaken conclusions about the current and potential global impacts of GM crops based on a limited number of studies conducted only in the United States.   It is true that currently commercialized GM crops have had a relatively modest impact on yields in the United States, although the recent introduction of drought-tolerant corn has likely had a more significant impact in areas where rainfall was limited. This modest impact is not surprising, as farmers here, as in other developed countries, have access to many pest-management tools [...]

GMO Basics How GMOs Are Made


Q: It is difficult for me to see how the growing world population could be fed with only organically grown food. If GMO crops were eliminated, what would be the effect on the worlds food supply?

Answered By Janet Carpenter - Jul 24, 2015

A: The number of people who are undernourished globally has been decreasing for over 20  years, with greater decreases in developing countries, but remains high, with an estimated 795 million people undernourished in 2015 (FAO 2015).  As the world population increases in the coming decades, the number of people at risk of hunger is expected to increase.  The causes of hunger are complex, including slow economic and less inclusive economic growth, political instability, lack of social protections and natural and human-induced disasters.  However, a key to making progress is inc [...]


Q: why are g.m. wheat corn being held up as necessary to feed a.growing population when we can grow a thousand times more weight of food per acre with conventional farming of cabbages?

Answered By Janet Carpenter - May 18, 2015

A: Moderator Note:  This response was drafted with input from Dr. Felicia Storer,    Your question points to an important challenge facing the world’s agricultural systems, which is how we will feed an estimated 2 billion more people by 2050 who increasingly demand meat, eggs and dairy in their diet.  While in the past we have cleared wild lands to grow more crops, the availability of new land is constrained, and we have a better understanding of the negative environmental impacts of clearing land for crop production.  Therefore, increased crop production will ha [...]



Q: what is the average crop yield for GMO and nonGMO canola in the USA

Answered By Janet Carpenter - Apr 12, 2016

A: Unfortunately, there are no publicly available data comparing average crops yields of GM and non-GM canola in the U.S., due to the relatively small acreage grown in the U.S. (1.8 million acres planted in 2015 compared to 82.7 million acres planted for soybeans). To see my response to a similar question regarding GM and non-GM soybean yields in the U.S., click here. [...]


Q: What is the average crop yield for GMO and nonGMO soybeans in the USA?

Answered By Janet Carpenter - Apr 12, 2016

A: The most recent data available from USDA on GM and non-GM soybean yields in the U.S. is from 2006, when GM herbicide tolerant soybean adopters were found to have a 3 percent yield advantage over non-adopters on average. (See 2014 USDA Economic Research Service Report, Genetically Engineered Crops in the United States.) However, it is important to keep in mind that average differences may be driven by other factors than the GM herbicide tolerance trait, such as other characteristics of the varieties being grown and/or management ability of farmers, etc., which may be systematically different be [...]

GMOs & Farmers