MARKETING AND ECONOMICS HORTSCIENCE 41(5):1259–1262. 2006. Conjoint Analysis Reveals Consumers Prefer Long, Thin Asparagus Spears Bridget K. Behe 1,2 Department of Horticulture, Michigan State University, East Lansing, MI 48824-1325 Additional index words. consumer, marketing, survey, vegetable Abstract. Michigan fresh asparagus marketers were interested in profiling asparagus consumers in the Northeast and Midwest with regard to preferences, purchases, preparation, and consumption. A computer-assisted survey was conducted with a total of 1126 respondents representative of the population on average in 12 selected states in the Northeast and Midwest. Even though the U.S. Department of Agriculture recom- mends adults consume three servings of vegetables daily, on average over the 2 weeks before taking the survey, 62% did not. Only 39% of the persons in the sample ate fresh asparagus in the 4 weeks preceding the survey. Twenty-five percent ate it steamed on the stovetop. The conjoint analysis accounted for 63% of the variance in asparagus preference with attribute relative importance decreasing from price (42.0%), to brand (29.9%), to spear diameter (23.5%), to spear segment (4.6%). Light users consumed fresh asparagus at least once in the 4 weeks before the survey, during the peak fresh asparagus season. The potential to increase consumption in this large group (28% of the sample but 71% of asparagus consumers) is tremendous. They placed high relative importance on price per pound and will likely be the more price-sensitive group. If their consumption can be increased by one more asparagus consumption event per month, it could increase asparagus demand by 14%. Results show there is good market potential for a prepack- aged fresh asparagus product in the Northeast and Midwest. Among vegetables, asparagus (Asparagus officinalis L.) is the leading supplier of folic acid for human nutrition, which is necessary for blood cell formation, growth, and pre- vention of liver disease. Folacin plays a sig- nificant role in the prevention of neural tube defects, such as spina bifida, that cause paralysis and death in infants. Asparagus is low in calories, contains no fat or cholesterol, is very low in sodium, and is a good source of potassium, fiber, thiamin, B6, and one of the richest sources of rutin, a chemical that strengthens capillary walls (Michigan Aspar- agus Council, 2005), making asparagus a wise choice for health-conscious consumers. The United States is the third leading world producer of asparagus behind China and Peru. In 2003, domestic producers grew 57 m kg. and imported 84 m kg. of asparagus, exporting only 14 m kg. California, Wash- ington, and Michigan were the top three producing US states for fresh market aspar- agus. The fresh market crop was valued at $137 million in 2002. Per capita consumption averaged 0.43 kg. from 2000 to 2002, up 60% from a decade ago and three times greater than 20 years ago (USDA, 2005). The US Department of Agriculture (USDA) recommends Americans consume three servings of vegetables daily, but most consumed only half that recommended amount (Reed, Frazao, and Itskowitz, 2004). These researchers showed that 57% of vegetables were least expensive in their raw form. Of the 154 forms of fruits and vegetables investigated, half cost $0.25 per serving or less. Among the 30 vegetables studied, potatoes were the most widely con- sumed vegetable (4 billion lb.), followed by tomatoes (1.6 billion lb.), onions (1.3 billion lb.), and corn (1.1 billion lb.). Asparagus ranked 18th in consumption of the vegetables studied, with Americans eating 127.5 million lb. in 1999, or 316 million servings. With the rising popularity of fresh prod- ucts ready for consumption, the Michigan Asparagus Advisory Board was interested in developing a fresh asparagus product ready for consumption in a microwaveable pack- age. The cleaned and packaged asparagus would be ready for cooking in a microwave, which would reduce consumer’s preparation time. However, no information has been published on asparagus consumption and consumer preferences. This study was de- veloped to investigate consumer purchases, preparation, consumption, and preferences of fresh asparagus in the Midwest and north- eastern United States, markets most proxi- mate to Michigan asparagus production. Materials and Methods A survey was developed with questions to determine vegetable consumption behavior and, in particular, asparagus purchasing, pre- paration, and consumption. The survey pro- tocol and instrument were approved by the University Committee on Research Involving Human Subjects before implementation. In addition to purchasing, preparation, and consumption questions, a conjoint study was constructed to determine the relative importance of four asparagus attributes: spear diameter, length and segment used, price, and brand name. Conjoint analysis allowed researchers to investigate simulta- neously a number of product attributes and determine the relative importance of each attribute in the consumer’s preference. Others used this method to determine con- sumer preferences for bell peppers (Frank et al., 2000), geraniums (Behe et al., 1999), outdoor ornamental plants (Townsley–Bras- camp et al., 1995), residential landscapes (Behe et al., 2005a), and table-top Christmas trees (Behe et al., 2005b). An additive model was used in which the preference for each factor was added to form the overall preference for a particular plate of asparagus. For each factor, scientists identi- fied a hierarchical set of levels to investigate. Two spear lengths were identified: short spears measured 7.5 cm and long spears were 15 cm long, measured from the spear tip. Spear diameter was either small (<1 cm) or large ($1 cm), measured 15 cm from the tip. Spear segment used was either tips (top 7.5 or 15 cm) or tips and cuts (top 7.5-cm segment and subsequent 7.5-cm segment). Price was identified at three price points: $1.49, $2.25, and $2.99/lb. Brand name was the final vari- able considered. One currently marketed brand name (although not for fresh aspara- gus) was used with two potential names under consideration by asparagus marketers: Green Giant, Sweet Tips, and Tender Tips. A fourth brand alternative was given as a ge- neric label. The design was a 2 · 2 · 3 · 4 factorial. Researchers reduced the number of combinations required from 48 to 16 by using a partial factorial design, while maintaining factor orthogonality, which decreased poten- tial participant fatigue. Participants were asked to rate ‘‘how much they liked’’ each plate of asparagus on a 5-point Likert scale (1 = like very little, 5 = like very much). Conjoint analysis defines the overall con- sumer preference for a particular product, in this case a plate of asparagus, as the sum of the part-worths, also defined as utilities, for each factor level. Conjoint and other statisti- cal analyses were completed using SPSS 10.0 (SPSS, Inc., Chicago, Ill.). Fresh asparagus spears were harvested from a Michigan farm 2 d before photograph- ing and stored in a 4.4 °C cooler. Spears were washed and sorted by diameter: <1 cm was classified as small, $1 cm was classified as large. Spears were trimmed with a knife to 15-cm segments from the top of the spear (long) or 7.5 cm (short). A professional photographer took digital images of aspara- gus spears on 26 May 2005 (Fig. 1). A visually similar number of spears were placed on a 20-cm-diameter white plate with a U.S. coin added as a scale reference. Knowledge Networks was subcontracted to provide a scientific probability sample of Received for publication 7 Mar. 2006. Accepted for publication 27 Apr. 2006. This research was generously funded through the Michigan State University Center for Product Agriculture with Project GREEEN funds and with USDA and Michigan Asparagus Advisory Board funds. 1 Professor. 2 To whom reprint requests should be addressed; e-mail behe@msu.edu. HORTSCIENCE VOL. 41(5) AUGUST 2006 1259