Survey data to assess consumers’ attitudes towards circular economy and bioeconomy practices: A focus on the fashion industry

Abstract

This data article presents data collected through a survey with the aim of understanding consumers’ behavior in the fashion industry. The analyses of these data are elaborated in the article “The circular economy and bioeconomy in the fashion sector: Emergence of a “sustainability bias”” (Colasante and Adamo 2021). As highlighted in the literature, the fashion industry contributes significantly to environmental pollution in all steps, from the production to the delivery. Often, consumers are not aware of the impact of their fashion habits on the environment and this led to the emergence of the well-known fast fashion phenomenon. Even though there is a lack of evidence on this topic, shifting consumers to embrace bioeconomy as well as circular economy principles constitutes a possible solution to reduce the impact of the fashion sector on the environment. We collected these data on consumers’ habits and preferences regarding both bioeconomy and circular economy by means of a questionnaire in which a total of 402 Italian people took part by using Amazon Mechanical Turk (MTurk) platform. This paper aims at presenting the data split in the three main blocks: (i) consumer perception; (ii) purchasing habits; and (iii) consumers’ willingness to pay (WTP). The results obtained are of interest to citizens, business, academics and policy makers to understand consumers’ perception of sustainability in the fashion industry. The proposed dataset can be replicated on a global scale, on specific market segments of the fashion industry and can be used to compare the perception of the circular bioeconomy in other sectors.

Specifications Table

Subject	Economics
Specific subject area	Bioeconomy Circular economy
Type of data	Table Figure
How data were acquired	Survey data were gathered using an online survey platform (Amazon MTurk).
Data format	Raw Analyzed
Parameters for data collection	The survey data were obtained from 402 respondents living in Italy who voluntary decided to answer to the questionnaire. No specific constraints or requirements, except for the nationality, were imposed.
Description of data collection	The questionnaire was published in the Amazon MTurk platform. The survey was available from June to August 2021.
Data source location	City: Rome Country: Italy Latitude and longitude: 41°53′30.95"N, 12°30′40.79"E
Data accessibility	Repository name: Zenodo Data identification number: 10.5281/zenodo.6537443 [2] Direct URL to data: https://zenodo.org/record/6537443
Related research article	Authors’ name: Annarita Colasante, Idiano D'Adamo. Title: The circular economy and bioeconomy in the fashion sector: Emergence of a “sustainability bias” Journal: Journal of Cleaner Production DOI: https://doi.org/10.1016/j.jclepro.2021.129774

Value of the Data

• •The data submitted to the Data in Brief are important to ensure more transparency in the analysis carried out in the co-submitted article [1].
• •The data contains consumer preferences and habits related to the purchase of second-hand clothes and clothes made from bio-based materials.
• •The primary beneficiaries of the dataset include: consumers who can use these data to compare their behaviors and improve their sustainability knowledge; businesses that can gain insight into citizen preferences to select appropriate green strategies; Policy-makers can infer implications for facilitating the green transition.
• •Other researchers may use these data to conduct cross-cultural as well as cross-country comparisons, looking for similarities and differences in the consumers’ attitudes toward both circular economy and bioeconomy in clothes purchasing.
• •The circular premium should be investigated on a larger sample of products and also proposing comparisons across countries.

1. Data Description

European countries are pursuing the objective to meet the sustainable development goals requirements. The most effective way to reach such goals is to promote the transition from linear to circular economy together with the promotion of a more sustainable life-style. The pillars of circular economy are: reduce, re-use, and recycle. The literature is plenty of scientific contributions focusing on the adoption of circular practices from the firms’ side but the analysis of consumers behavior is still poor [3], [4], [5]. One of the main motivations of this scarce evidence is the difficulty to observe and measure consumers’ habits [6]. The survey was designed to capture respondents’ attitudes towards the circular economy and the bioeconomy within the fashion sector and also to grasp their knowledge with respect to sustainable fashion. The fashion industry has a great negative impact on the environment and, in the last decades, consumers habits switched into less and less sustainable purchasing option [7]. Indeed, the emergence of the fast fashion phenomenon in which more than two collections per year are proposed coupled with very convenient prices (due to the poor quality of clothes) have brought to the production of tons of waste in a short time. We strongly believe that, in order to switch from this vicious cycle to a virtuous one, firms and consumers need to change their conduct: on the one hand, firms are using bio materials and are designing more sustainable products; on the other hand, consumers need to reduce their consumption or may opt for re-using (second-hand market). In addition, the use of sustainable products should not push to consume more than necessary, generating phenomena known as circular economy rebound [8]. The identification of a sustainability bias highlights the urgency of strengthening social analysis, an aspect that has been highlighted in the literature in the context of the circular economy [9,10].

The questionnaire we administered to 402 Italian people included approximately 35 items. Overall, our raw data includes: 11 questions whose answers were measured as a 5-points Likert scale, 1 question evaluated over a 10-points value scale, 4 yes/no questions, 11 closed-ended questions and 7 open questions. The distributions of answers for each question are reported in Tables 1–4. The items can be arranged in three main groups of variables. The first group (group A) focused on perceptions of sustainable fashion – Table 1. Items in this part were designed to figure out if people are aware of the pollution generated by fashion industry and, furthermore, to determine what are the main characteristics subjects attribute to sustainable fashion.

Table 1.

Questions belonging to group A: definition and perception of sustainable fashion. For each question we show the frequency distribution.

Variable	Range
Pollution synthetic
How much do you agree with the following statement: Chemical pollutants are produced during the production of synthetic fibers such as polyester?
Strongly disagree	1.50%
Disagree	5.74%
Undecided	26.43%
Agree	45.39%
Strongly agree	20.95%
Pollution natural
How much do you agree with the following statement: Chemical pollutants are produced during the production of natural fibers such as cotton?
Strongly disagree	4.99%
Disagree	20.20%
Undecided	40.40%
Agree	25.94%
Strongly agree	8.48%
Pollution dye
How much do you agree with the following statement: Air pollution can occur during some common textile dyeing processes?
Strongly disagree	0.50%
Disagree	7.23%
Undecided	27.68%
Agree	43.89%
Strongly agree	20.70%
Pollution water
How much do you agree with the following statements: a lot of water is used during the process of dyeing and finishing clothes?
Strongly disagree	0.50%
Disagree	5.49%
Undecided	23.69%
Agree	38.40%
Strongly agree	31.92%
Biodegradable
How much do you agree with the following statement: all natural fibres are biodegradable?
Strongly disagree	1.49%
Disagree	13.43%
Undecided	33.43%
Agree	30.45%
Strongly agree	21.19%
Sector sustainability
Define the sector that is most related to sustainability.
Environment	44.89%
Economy	7.48%
Society	2.24%
A mix of all items	45.39%
Phases sustainability
Define which phase is strictly related to sustainable fashion.
Design	9.23%
Production	37.16%
Delivery	4.74%
Selling	1.25%
After sale	1.75%
A mix of all items	45.89%
Sustainable fashion
In your opinion, which of these products can be classified as belonging to sustainable fashion?
Second-hand clothes
1	2.24%
2	3.74%
3	6.23%
4	5.24%
5	6.23%
6	15.46%
7	18.20%
8	19.20%
9	13.72%
10	9.73%
Bio-based clothes
1	3.74%
2	2.24%
3	4.99%
4	4.74%
5	8.73%
6	11.47%
7	22.44%
8	18.45%
9	16.71%
10	6.48%
Clothes produced respecting workers conditions (e.g., no child work)
1	3.74%
2	2.24%
3	5.74%
4	3.24%
5	10.22%
6	15.46%
7	16.96%
8	15.96%
9	16.96%
10	9.48%
Clothes produced respecting workers conditions (e.g., no child work) and with bio fibers
1	0.75%
2	0.25%
3	3.99%
4	3.24%
5	7.23%
6	9.23%
7	13.22%
8	18.95%
9	25.69%
10	17.46%
Clothes characteristics
When buying a cloth for yourself, how much do you consider the following items important? is produced in an environmentally respectful manner
Not at all	4.24%
Slightly	18.95%
Moderately	40.65%
Important	25.94%
Very important	10.22%
is from a well-known brand
Not at all	28.68%
Slightly	33.67%
Moderately	26.18%
Important	9.23%
Very important	2.24%
is inexpensive
Not at all	1.00%
Slightly	5.74%
Moderately	38.40%
Important	38.40%
Very important	16.46%
is good quality
Not at all	0.50%
Slightly	3.74%
Moderately	18.95%
Important	44.64%
Very important	32.17%
is trendy (fashion)
Not at all	13.72%
Slightly	32.17%
Moderately	37.16%
Important	13.72%
Very important	3.24%
is versatile
Not at all	1.25%
Slightly	6.48%
Moderately	25.19%
Important	51.12%
Very important	15.96%
is something that you need
Not at all	1.00%
Slightly	2.99%
Moderately	19.95%
Important	51.62%
Very important	24.44%
is available in your size
Not at all	0
Slightly	2.99%
Moderately	8.98%
Important	34.66%
Very important	53.37%
is comfortable
Not at all	0.25%
Slightly	2.74%
Moderately	11.97%
Important	40.40%
Very important	44.64%
is easy to care for
Not at all	2.49%
Slightly	13.47%
Moderately	32.17%
Important	35.66%
Very important	16.21%
has a good value for money
Not at all	0
Slightly	2.74%
Moderately	12.22%
Important	44.64%
Very important	40.40%
is from a prestigious brand
Not at all	28.68%
Slightly	33.67%
Moderately	26.18%
Important	9.23%
Very important	2.24%

Table 4.

Questions related to socio-demographics characteristics... For each question we show the frequency distribution. Notice that for the variables Age and Number of people living in the household the average values are shown.

Variable
Pro-environmental attitude
Obtained as the normalized sum of the following items:
How often do you ccorrectly recycle waste materials produced daily (separate collection)?
Never	0.50%
Rarely	4.49%
Sometimes	9.48%
Often	27.18%
Always	58.35%
How often do you read the labels of the products (food, clothes, etc.) to check if they have been produced respecting the environment?
Never	4.74%
Rarely	12.72%
Sometimes	32.67%
Often	31.92%
Always	17.96%
How often do you avoid buying products from companies that do not respect the environment in their production cycles?
Never	8.73%
Rarely	21.45%
Sometimes	30.67%
Often	29.43%
Always	9.73%
How often do you buy products with little packaging or recyclable packaging?
Never	5.99%
Rarely	16.46%
Sometimes	30.67%
Often	35.66%
Always	11.22%
How often do you use public transport to reduce CO2 emissions?
Never	17.96%
Rarely	21.20%
Sometimes	23.94%
Often	23.19%
Always	13.72%
How often do you purchase products in packs that can be refilled / reused?
Never	3.49%
Rarely	16.96%
Sometimes	29.18%
Often	34.91%
Always	15.46%
How often do you donate money to associations for the protection of the environment?
Never	31.67%
Rarely	28.68%
Sometimes	23.69%
Often	12.47%
Always	3.49%
How often do you buy reusable rather than disposable goods?
Never	2.49%
Rarely	10.22%
Sometimes	26.18%
Often	38.90%
Always	22.19%
Pro-environmental attitude (clothes)
Obtained as the sum of the following items:
How often do you buy used clothes?
Never	38.90%
Rarely	23.44%
Sometimes	25.19%
Often	10.72%
Always	1.75%
How often do you read the labels of clothes to check if they have been produced respecting the environment?
Never	6.73%
Rarely	24.19%
Sometimes	27.93%
Often	28.93%
Always	12.22%
How often do you select clothes that require colder wash water temperatures or less ironing?
Never	22.19%
Rarely	21.45%
Sometimes	25.94%
Often	24.19%
Always	6.23%
How often do you select items that you can wear for a long time versus items that go out of style quickly?
Never	3.74%
Rarely	9.23%
Sometimes	21.70%
Often	40.15%
Always	25.19%
How often do you buy clothes produced with natural fibers?
Never	5.74%
Rarely	18.70%
Sometimes	36.66%
Often	29.68%
Always	9.23%
How often do you buy clothes with labels certifying respect for the environment?
Never	8.73%
Rarely	22.94%
Sometimes	33.92%
Often	27.18%
Always	7.23%
Female
Please indicate your gender
Female	60.86%
Male	39.14%
Age	33.54
How old are you?
Education
What is the highest level of education you have achieved?
Primary school	0.25%
Middle school	2.24%
Secondary school	38.65%
Postsecondary education	52.62%
PhD	6.23%
Number of people in the household	3.40
How many people does your household consist of?
Income
What is your income?
0-15000€	27.54%
15000€-30000€	35.33%
30000€-45000€	20.96%
45000€-60000€	9.58%
60000€-75000€	2.40%
75000€-100000€	2.99%
more than 100000€	1.20%
Region
In which region do you live?
Abruzzo	14.46%
Basilicata	1.25%
Calabria	1.00%
Campania	7.23%
Emilia Romagna	3.99%
Friuli Venezia Giulia	1.25%
Lazio	15.71%
Liguria	2.00%
Lombardia	14.46%
Marche	2.00%
Molise	1.50%
Piemonte	0.50%
Puglia	8.48%
Sardegna	5.99%
Sicilia	1.75%
Toscana	3.99%
Trentino Alto Adige	7.23%
Umbria	1.25%
Veneto	1.50%
	4.49%

The second group of variables (group B), constitutes the core of the survey – Table 2. Indeed, this part were useful to investigate individuals purchasing habits about second-hand and/or bio-based clothes. We also ask subjects to provide their main reasons for buying (or not) such kind of clothes – Fig. 1. This part allows us to understand how much people are used to do sustainable shopping and, furthermore, to draw some hints about the key variables policy makers need to consider for encouraging people to take sustainability more in consideration. Notice that only subjects who declared to have never bought either second-hand or biobased clothes provided an answer for questions included in Motivation not to buy second-hand and Motivation not to buy bio-based.

Table 2.

Questions belonging to group B: clothes purchasing habits. For each question we show the frequency distribution.

Variables
Buy bio-based clothes
Have you ever bought (at least once) bio-based clothes?
Yes	83.46%
No	16.54%
Buy bio-based items
Have you ever bought (at least once) bio-based items?
Yes	79.55%
No	20.45%
Buy second-hand clothes
Have you ever bought (at least once) second-hand clothes?
Yes	50.12%
No	49.88%
Buy second-hand items
Have you ever bought (at least once) second-hand items?
Yes	77.56%
No	22.44%
Motivation second-hand
Please indicate how important the following reasons are when choosing to buy second-hand clothing:
Economic reasons
Not at all	0
Slightly	20.40%
Moderately	30.85%
Important	33.33%
Very important	15.42%
Quality of the product
Not at all	0
Slightly	7.96%
Moderately	27.86%
Important	39.30%
Very important	24.88%
Reduce pollution related to production of new clothes
Not at all	4.98%
Slightly	17.91%
Moderately	28.36%
Important	32.34%
Very important	16.42%
Find exclusive items
Not at all	7.96%
Slightly	20.90%
Moderately	33.83%
Important	24.88%
Very important	12.44%
My peers bought similar clothes
Not at all	45.77%
Slightly	31.34%
Moderately	13.93%
Important	7.96%
Very important	1.00%
Use garments that have not yet finished their life cycle
Not at all	4.98%
Slightly	14.93%
Moderately	34.33%
Important	34.83%
Very important	10.95%
Motivation bio-based
Please indicate how important the following reasons are when choosing to buy bio-based clothing:
Economic reasons
Not at all	5.07%
Slightly	27.76%
Moderately	31.94%
Important	23.58%
Very important	11.64%
Quality of the product
Not at all	1.19%
Slightly	10.15%
Moderately	28.36%
Important	40.60%
Very important	19.70%
Reduce pollution related to production of new clothes
Not at all	1.49%
Slightly	13.43%
Moderately	33.43%
Important	30.45%
Very important	21.19%
Find exclusive items
Not at all	22.09%
Slightly	37.61%
Moderately	23.58%
Important	12.54%
Very important	4.18%
My peers bought similar clothes
Not at all	47.76%
Slightly	26.57%
Moderately	15.52%
Important	8.96%
Very important	1.19%
Motivation not to buy second-hand
Could you indicate how important are the following reasons for not buying second-hand clothing?
Poor availability of dedicated applications
Not at all	11.06%
Slightly	31.16%
Moderately	36.18%
Important	17.59%
Very important	4.02%
Poor availability of dedicated shops
Not at all	6.53%
Slightly	22.61%
Moderately	28.64%
Important	30.65%
Very important	11.56%
Poor impact on the environmental protection
Not at all	14.07%
Slightly	33.67%
Moderately	36.18%
Important	14.07%
Very important	2.01%
Poor hygiene
Not at all	7.04%
Slightly	6.53%
Moderately	28.14%
Important	24.62%
Very important	33.67%
Poor quality
Not at all	7.04%
Slightly	26.13%
Moderately	35.18%
Important	24.62%
Very important	7.03%
It is difficult to find the proper size
Not at all	6.03%
Slightly	17.09%
Moderately	29.65%
Important	36.18%
Very important	11.06%
It is difficult to find trendy clothes
Not at all	16.16%
Slightly	24.75%
Moderately	28.79%
Important	22.73%
Very important	7.58%
Motivation not to buy bio-based
Could you indicate how important are the following reasons for not buying bio-based clothing?
Poor availability of dedicated applications
Not at all	9.23%
Slightly	26.15%
Moderately	43.08%
Important	13.85%
Very important	7.69%
Poor availability of dedicated shops
Not at all	4.62%
Slightly	7.69%
Moderately	30.77%
Important	43.08%
Very important	13.85%
Poor impact on the environmental protection
Not at all	16.92%
Slightly	29.23%
Moderately	36.92%
Important	16.92%
Very important	-
Clothes produced with bio fibers are difficult to find
Not at all	4.62%
Slightly	26.15%
Moderately	33.85%
Important	24.62%
Very important	10.77%
They have no style details compared with other clothes
Not at all	36.92%
Slightly	38.46%
Moderately	15.38%
Important	4.62%
Very important	4.62%
They are too expensive
Not at all	1.54%
Slightly	10.77%
Moderately	35.38%
Important	33.85%
Very important	18.46%
It is difficult to find trendy clothes
Not at all	41.54%
Slightly	32.31%
Moderately	13.85%
Important	12.31%
Very important	-
Poor quality
Not at all	23.08%
Slightly	24.62%
Moderately	32.31%
Important	12.31%
Very important	7.69%

Fig. 1.

Distribution of answers related to the main characteristics of both bio-based and second-hand clothes. The graph on the top shows the percentage of people that have ever bought either bio-based (blue bar) or second-hand (orange bar) clothes. The graph on the left-bottom reports the main characteristics people look for bio-based clothes whereas the graph on the right-bottom reports the same information for second-hand clothes.

Finally, the third part of the questionnaire was devoted to elicit subjects’ willingness to pay (WTP). In particular, the third group of variables (group C) provides information about respondents’ WTP for a t-shirt with (potentially) different characteristic (e.g. bio-based or produced with recycled materials) – Table 3.

Table 3.

Questions belonging to group C: willingness to pay for a white t-shirt (€/unit). For each question we show the frequency distribution. Notice that for the variables WTP new, WTP bio, WTP second-hand, WTP recycled and WTP certificate the average values are shown.

Variable
WTP new	9.63
[Picture of a white t-shirt] How much would you be willing to pay if the garment was new?
WTP bio	11.87
[Picture of a white t-shirt] How much would you be willing to pay if the garment was produced with bio materials?
WTP second-hand	4.16
[Picture of a white t-shirt] How much would you be willing to pay if the garment was used?
WTP recycled	10.36
[Picture of a white t-shirt] How much would you be willing to pay if the garment was produced with recycled materials?
WTP workers	11.9
[Picture of a white t-shirt] How much would you be willing to pay if the garment was produced respecting workers?
WTP bio certificate
How much more would you pay if there was a certificate that guarantees that the cloth is produced with bio materials?
Nothing	7.98%
Little amount	28.18%
Pay enough	50.12%
Large amount	13.72%
WTP second-hand quality certificate
How much more would you pay if there was a certificate that guarantees that the used cloth is a good quality?
Nothing	14.21%
Little amount	34.66%
Pay enough	42.14%
Large amount	8.98%
WTP workers certificate
How much more would you pay if there was a certificate that guarantees that the cloth is produced respecting workers?
Nothing	10.97%
Little amount	24.44%
Pay enough	45.39%
Large amount	19.20%
WTP workers and environmental certificate
How much more would you pay if there was a certificate that guarantees that the cloth is produced respecting both workers and the environment?
Nothing	7.48%
Little amount	21.45%
Pay enough	45.64%
Large amount	25.44%
WTP recycled
How much more would you pay if there was a certificate that guarantees that the cloth is produced from recycled materials?
Nothing	11.22%
Little amount	31.42%
Pay enough	45.89%
Large amount	11.47%

Besides the main variables of interest mentioned in the previous tables, we also ask for socio-demographics characteristics and, moreover, we try to assess the pro-environmental attitude of participants (Table 4). It is worth noting that the panel of respondents has an average age of 33.5 years and we can therefore define it as young. This value is about 13 years younger than the average age of the Italian population.

2. Experimental Design, Materials and Methods

The survey was designed to follow a descriptive online cross-sectional survey design and, according to the taxonomy proposed by Sovacool et al. [11], was based on a method characterized by a behavioral approach. Indeed, we design questions by taking into account suggestions from different disciplines such as economics, psychology and engineering. The main aim of the work is to grasp consumers’ attitude toward sustainable purchasing in the fashion field. In particular, given the great attention devoted in the last years to the transition from linear to circular paradigm, we focused on the second-hand market. We also add questions to identify consumers’ behavior towards bio-based clothes. This implies that the added value of this work relies on the possibility to compare two key sectors in the sustainable transition: bioeconomy and circular economy.

The procedure we follow to build the questionnaire can be summarized in the following steps: (i) define the research question and, hence, the focus of the questionnaire; (ii) draw up a list of questions taking as a benchmark the approach used by Kim [12]; (iii) submit the preliminary list of questions to a submitted to a pool of experts to validate its appropriateness before the launch on the web; (iv) dissemination of the questionnaire to Italian people registered in the Amazon Mechanical Turk platform.

In order to define the research question, we identified a gap in the literature since the majority of scientific contribution focused either on circular economy or bioeconomy. Furthermore, we decided to focus on the fashion industry since it is responsible for a huge share of pollution in the last decade. Once we had clearly identified the goal of our research, we looked at the papers in that field that already implemented survey as a method to collect data in order to take a cue for properly designing our questionnaire. The questionnaire included three main blocks: in the first part we focus on consumer perception of sustainable fashion. We tried to figure out both consumers’ awareness on the pollution imputable to the fashion industry and the main characteristics consumers ascribe to sustainable fashion. The second block was designed to collect the most important information constituted the core of the survey: we ask respondents to declare whether they buy or not second-hand clothes and bio-based clothes. We move forward by asking them to provide the main reasons why they do (or do not) buy these kinds of clothes. In the last part of the questionnaire we elicit consumers’ WTP for a white t-shirt with (potential) different characteristics such as be second-hand or be bio-based or be produced with recycled materials or be produced with respect for workers' rights – Fig. 2.

Fig. 2.

General framework to describe the main aim of the data collection and structure

Once a draft of the survey was ready, we validated the adequacy of the proposed questions to the research objective. For this purpose, we selected a panel of experts composed of academics and managers with experience in sustainable fashion in order to understand both the suitability of the questions and to test the appropriateness of the time needed to carry them out. Based on their suggestions, some changes were made as well as some questions were removed and/or added. Since we introduced some filter questions (e.g., people who answer “yes” or “no” to some questions faced different sequences of questions), the time employed in order to complete the questionnaire ranged from 12 to 20 min. In general, the average time needed to complete the survey was estimated around 16 min.

As soon as we implemented all the experts’ suggestions, we disseminated the questionnaire by using Amazon Mechanical Turk platform. This platform allows to the requesters to publish the so-called HIT (Human Intelligence Task) and workers may decide if they are willing to complete the task in exchange for a small amount of money. We solely imposed two restrictions to select participants: be Italian and have an approval rating higher that 95%.1 The survey was feasible from June to August 2021 and we collected a total of 402 responses.

Once we collected the answers, data were organized and analysed by using both statistical and econometric tools. The major aim was to estimate the main determinants of WTP for both clothes made from bio-based materials and second-hand clothes. Results may be consultable in the paper [1].

Ethics Statement

Given that the research is a non-experimental voluntary survey, no ethical approval is necessary. Furthermore, the self-administered survey that is non-experimental in nature was conducted under complete anonymity for the participants. No personal or sensitive information that can be used to identify the respondents were collected. Besides, the consent of the respondents to partake in the online survey were seek before the survey was executed by including an electronic informed consent in the online survey form.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article.

Data Availability

• Dataset fashion (Original data) (Zenodo).