Abstract
The objective of this study is to empirically test the validity of the cost stickiness theory for the companies operating in the BIST Chemical, Pharmaceutical, Petroleum, Rubber and Plastic Products sector for the period of 2010-2019. In the study, three alternative cost variables such as cost of sales, general administrative expenses and marketing, selling and distribution expenses were employed to represent the cost behavior of firms. After controlling the firm size variable in the study, the findings obtained within the framework of the applied two-way static panel data regression analysis indicate that the expenses (costs) of the firms in the sample exhibit an asymmetrical behavior, which shows that the theory of cost stickiness is valid for the examined sector. Therefore, the empirical findings from this study support the asymmetric cost behavior (cost stickiness) view, which argues that costs move asymmetrically, rather than the traditional cost behavior view, which assumes that costs move symmetrically. Therefore, the results of this study are important for all stakeholders related to the sector. As a result, a better understanding of cost behavior in terms of companies can contribute to a more effective cost planning in companies and to increase the profitability and value of the company.