The increasing popularity of social media worldwide provides us with an opportunity to understand social, cultural, and environmental issues about people’s perception of sustainability. The article aims at identifying the main topics of communication related to hashtag # sustainability based on a communication analysis on the Twitter network. We investigated the perception of sustainability using data from 414,926 Twitter interactions by 223,476 users worldwide. The data were recorded between April 17, 2018 and July 12, 2019. We identified Innovation, Environment, Climate Change, Corporate Social Responsibility, Technology, and Energy as key hashtags in the field of sustainability. In conjunction with this, we identified the six following communities: (1) Environmental Sustainability, (2) Sustainability Awareness, (3) Renewable Energy and Climate Change, (4) Innovative Technology, (5) Green Architecture, and (6) Food Sustainability. The usage of these communities is applicable in marketing communication as well as in the Corporate Social Responsibility activities of the given companies. The results of the analysis give the organizations a possible direction for their sustainable business model improvement via the contribution of society´s voice.

Small farmers represent a majority of the European Union (EU) farming sector and are considered the cornerstone of both the current and future sustainable EU agriculture. The dynamic complexity of livestock systems hinders the understanding of its behaviour, as well as recognizing the causes of problems and sources of resistance to applied policies and strategies. Livestock system behaviour needs to be understood in order to find leverage points and identify efficient solutions. The presented study depicts issues of small-scale beef cattle farmers in the market environment from a systemic perspective. The common complexity of managing a company increases with biological processes characterized by very long time periods, especially in the case of beef cattle farming. The scenarios analysed by the computer simulation model presented in the study evaluate the benefits of basic diversification into meat processing and a farm-to-table approach. The direct contact of the farmer with the final consumers represents increased demand and requirements on farmers’ entrepreneurship; nevertheless, such a strategy is a significant growth driver that allows faster maximisation of the farm’s output, accelerates the return of the investments, strengthens the market position of the farmer, and increases the farm’s sustainability.

Th e paper deals with the estimation and analysis of the average age and the age structure of machinery and equipment in agriculture. Th e development of the average age of machinery and equipment could be used as an indicator of the modernisation process and the picture of investment support in the industry. For the purposes of the analysis, the offi cial model of the perpetual inventory method is transformed into the Markov chain model. Th e analysis shows signifi cant differences in the institutional sectors. Th e average age of machinery and the age distribution depicts the situation in agriculture and it indicates the lower competitiveness of small farmers. Th e paper contains the prognosis of development of the average age of machinery and equipment in the case of permanent investment on the level of the current year. Th e international comparison shows that the average age of machinery and equipment in the Czech Republic is close to the level of developed countries. However, the estimated development shows a decreasing average age of the machinery and equipment.

Th e paper deals with the dynamic simulation of the possible development scenarios of small farmers. Th e model is based on the offi cial data sources but also on the qualitative research of small farmers. Th e modelling structure refl ects the specifi cs of the examined fi eld and personal and social specifi cs of small farmers. For the purposes of the analysis, the business model describes the value creation in the small and individual farms, thereafter the model is extended into the dynamic simulation model and the selected scenarios of development are simulated. Th e analysis shows the impact of the current setup in the fi eld. Despite the fact that the paper contains the optimistic scenarios, a simple change of parameters leads to an unsustainable situation. Th e pessimistic scenarios grow from the realistic conditions when the parameters refl ect the recent period settings. Th is clearly depicts the infl uence of the weak market position of the farmers and advocates the diversifi cation tendencies.

The paper deals with an estimate and analysis of the value of regional net fixed capital stock and the age structure of machinery and equipment in Czech agriculture. In order to perform such analysis, the official model of perpetual inventory method is transformed into the Markov chain model and applied on regional data separately. Regional net fixed capital stock is presented for the period of 2008-2013.The development of the average age of machinery and equipment comprises a potential indicator of the modernisation process in the industry. The analysis of the age structure is based on the structure heterogeneity indicator. For these purposes, the real age structure in each Czech region is compared with the theoretical stable and stationary structure. Currently, the most heterogeneous age structure of machinery and equipment occurs in Prague and the Karlovy Vary region. KeywordsAverage age of assets, Markov chain, fixed capital stock, perpetual inventory method, regional capital stock.