Abstract
An increasing body of literature identifies consumption habits, particularly of affluent population segments, as an important barrier and key lever of climate change mitigation efforts (Creutzig et al., 2016; IPCC, 2022; Mundaca et al., 2019; Poore & Nemecek, 2018). One area of such currently unsustainable consumption habits are food consumption patterns threatening global food security due to high diet-related greenhouse gas emissions, land and water use, biodiversity loss, as well as negative health consequences (Clark et al., 2020; Crippa et al., 2021; IPCC, 2022; Scarborough et al., 2023; Willett et al., 2019). Thus, there is a growing consensus in the literature that a demand-side shift toward more plant-based diets is a key lever to sustainably change the food system and dietary patterns (Jetzke et al., 2020; Rosenzweig et al., 2020; Willett et al., 2019). This is due to animal foods having a higher inefficiency in water, energy, soil, and land usage compared to plant-based foods, for example, due to animal feed production (Poore & Nemecek, 2018). Further, excessive meat consumption increases the risk for different health problems, such as obesity, cardiovascular diseases, and cancer (Jetzke et al., 2020). Yet, despite the well-understood negative consequences of meat consumption, average global meat consumption levels are still increasing due to an overall increasing demand, especially in developing and emerging countries, while demand is stagnating mostly on rather high levels in industrialized countries (Jetzke et al., 2020; OECD & FAO, 2021). Thus, there is an urgent need for strategies to encourage demand-side shifts toward more plant-based diets.
With the so-called Planetary Health Diet, the EAT-Lancet commission proposes a sustainable and healthy diet that includes a maximum of 15 kilograms of meat per person per year (Willett et al., 2019). However, changing consumer behavior in the realm of food is challenging. Individuals typically do not base their consumption decisions on rational arguments, nor are they perfectly informed. Instead, individuals often rely on simple cues or heuristics (Kahneman et al., 1982; Montibeller & von Winterfeldt, 2015), such as perceived naturalness, feelings of disgust, or trust in the food industry (Siegrist & Hartmann, 2020). Additionally, previously formed habits play a significant role in food decision-making (Rees et al., 2018; Saba & Di Natale, 1998), particularly regarding meat consumption (de Boer & Aiking, 2017). Those deeply rooted food consumption habits result, amongst others, from culture, traditions, learned behavioral patterns, values, and the social environment, and are therefore not easily changed (Constantino et al., 2022; Hartmann & Siegrist, 2020; Kukowski et al., 2023).
One important enabling factor that is increasingly being discussed to accelerate a shift toward more plant-based diets are meat substitute products. In the last years, the market for plant-based meat substitutes, such as plant-based burger patties, sausages, cold cuts, etc., was growing exponentially, although it is still relatively small compared to the global meat market (Polaris Market Research, 2020). Due to economies of scale and technological learning, especially plant-based meat substitute products become increasingly available and more affordable for consumers, as well as more like meat regarding their taste, texture, and appearance (He et al., 2020; Smetana et al., 2021). Although different studies still find that meat substitute products are on average perceived to be inferior to meat regarding taste, texture, and price (Michel et al., 2021; Taylor et al., 2022), others find that meat substitutes are perceived positively, especially regarding animal welfare, health, and the environmental impact (Fesenfeld et al., 2024; Michel et al., 2021; Taylor et al., 2022). However, we lack causal evidence about how experience with such substitute affects future consumption of meat substitute (i.e., substitute adoption rates) and whether more substitute consumptions leads to significant reductions in meat consumption (i.e. meat substitution effects) (Cuffey et al., 2022; Neuhofer & Lusk, 2022; Zhao et al., 2022).
Several, mainly observational and/or survey experimental studies, highlight the essential role of familiarity and repeated (positive) experiences with meat substitutes in influencing individuals’ attitudes, intentions, and subsequently potentially behavioral patterns (Fesenfeld et al., 2023; Graça et al., 2019; Hartmann & Siegrist, 2017; Hoek et al., 2013; Van Bergen et al., 2024). While some of the observational and survey-based studies do not find any positive effects of substitute experience on meat substitution nor substitute adoption (e.g., Cuffey et al., 2022; Van Bergen et al., 2024), other studies suggest that growing exposure to meat substitutes might alter consumers’ product perceptions, substitute adoption and meat substitution – at least for some products (Fesenfeld et al., 2023, 2024; Zhao et al., 2022). Overall, existing studies are thus inconclusive regarding the effects of meat substitute experience on adoption rates and substitution effects. In particular, we currently lack field-experimental studies, in which randomly selected treatment group from a larger population representative sample gains repeated experiences with meat substitute and subsequently their attitudes as well as real-world purchasing behaviors are compared to a control group without the exposure treatment. In this study, we close this research gap by conducting a population-representative survey- and field experiment in Switzerland.
Here, we build on dual process models of human decision making (Chaiken & Trope, 1999; Kahneman, 2011; van der Linden, 2014). According to the theory, it is crucial to differentiate between affective (System I) and rational (System II) decision making. System I, the affective (experiential) decision making system makes rather unconscious, intuitive, automatic decisions with low cognitive effort based on learned behavior and experience. In contrast, System II, the analytical (deliberative) decision making system makes conscious and reflected decisions with higher cognitive effort based on logical thinking, knowledge, and the available information. In decision-making, both systems typically work together to help individuals navigate various cognitive tasks. Food consumption preferences and resulting food consumption choices are typically dominated by System I, which builds on past experiences (Godfray et al., 2018; Smith & DeCoster, 2000). Thus, becoming familiar with and tasting meat substitute products can be a crucial first step towards changing habitual consumption patterns. This is confirmed by several studies showing that familiarity with meat substitutes - i.e. building experience with such products by consuming them repeatedly - is necessary to establish favorable attitudes towards consuming them (Fesenfeld et al., 2023; Hellwig et al., 2022; Onwezen et al., 2022; Siddiqui et al., 2022; Szenderák et al., 2022).
Thus, in the present study we contribute to the literature by causally analyzing the impact of repeated meat substitute experiences with high-quality plant-based meat substitutes on the intention to reduce meat consumption, to increase meat substitute consumption, to support food policy measures, as well as on the revealed purchasing patterns over time. To experimentally evaluate this, we conduct a survey and a field experiment with a representative sample of Swiss residents (obtained from the Federal Statistical Office) in cooperation with the Swiss retailers Coop and Migros and the Swiss plant-based meat substitute producers Planted and Green Mountain. The study was approved by the ETH Ethics Commission. In the first part of the study, we conduct a first survey wave to get to know individuals’ attitudes and intentions on meat and meat substitute consumption, as well as other important control variables influencing food consumption behavior. Then we randomly assign individuals to either the control group getting no substitute products or the treatment group that receives a package with meat substitute products from the Swiss brand Planted and/or vouchers to get meat substitute products from the Swiss brand Green Mountain to cook at home (enough for about 2 dishes) after the first survey wave has been completed. Following the treatment phase, we conduct a second survey wave to ask individuals about their attitudes and intentions on meat and meat substitute consumption post treatment. In the second field experimental part of the study, we then causally evaluate the impact of the random meat substitute experience treatment on individuals’ food purchasing behavior over time by obtaining food purchasing data via Migros and Coop (based on previous informed consent of the survey participants). To our knowledge, this is the first study to collect longitudinal, experimental data from a representative sample on the meat substitution effect and substitute adoption effect of gaining experience with meat substitute products. Furthermore, the study allows causal inference about the effect of gaining experience with meat substitutes on the size of the intention-behavior gap. Several scholars have emphasized the need for such experimental studies (Fesenfeld et al., 2023; Kwasny et al., 2022; Nguyen et al., 2022; Onwezen et al., 2022; Taufik et al., 2019). Furthermore, this study aims to explore the mediating factors of the plant-based meat substitute experience treatment, examining their relationship with stated and revealed consumption adaptations, as well as changes in policy perceptions resulting from experience with meat substitute products.
Based on a review of the existing literature, we formulated the a number of testable hypotheses on the effects of the experience treatment. These hypotheses are outlined in the section "Experimental Details".