بررسی نقش عدم اطمینان محیطی در رفتار هزینه ها؛ شواهدی از شرکتهای پذیرفته شده در بورس اوراق بهادار تهران

Journal of Accounting Advances (J.A.A)
Vol. 7, No. 2, 2015, Ser. 69/3
 
 
Extended Abstract
 
Investigating the Role of Demand Uncertainty in Cost Behavior; Evidences From Tehran Stock Exchange Firms
 
Dr. Ali Asghar Anvary Rostami*            Aidin Kiani**
 
Introduction
Understanding cost behavior is one of the important issues in management accounting. Principles of flexible budgeting is based on proportionate changes of costs with regards to changes at activity level. So such budgeting method which would not consider the relationship of cost behavior and uncertainty condition may lead to significant variances. Optimum choice of flexible or committed resource is one of the most important problems of managers.  “Integral to strategic cost management is the choice of procuring flexible versus committed resources conditioned on demand uncertainty” (Anderson et al. 2012). Prior research shows that costs respond less to decreases than increases in sales activity when firms invest in committed resources.
 
Research Questions and Hypotheses
This article concentrates on the role of demand uncertainty in cost behavior. The main question is:
Is there a significant relationship between demand uncertainty and cost behavior?
 
Hypotheses:
In order to find the answer to questions, two hypotheses are made:
H1: There is a positive relationship between demand uncertainty and cost of goods sold flexible behavior.
H2: There is a positive relationship between demand uncertainty and sales, general and administrative expenses flexible behavior.
 
Methods
The research method used in this article is multivariate regression analysis of the role of demand uncertainty in cost behavior of firms. We define cost behavior in terms of cost elasticity, which we consider it as the percentage change in costs for a one-percent change in sales. So, higher cost elasticity would indicate a more flexible cost structure.
 
Sample
The sample of this research is selected from the firms of Tehran stock exchange with constraints below:
1-   Financial firms have not been selected for analysis.
2-   Firms which their fiscal year end (1392/12/29) were selected.
3-   Firms which do not have 3 year ahead data have not been selected.
After considering the above conditions, 1340 firm-year observations were selected for analysis.
 
Models
Models (1) and (2) are considered to capture the relationship between demand uncertainty and cost behavior. Models (3) and (4) capture the relationship between cost changes and revenue changes. So the coefficients                          and  are metrics of cost elasticity or cost stikinees.
 
(1)
Model (1) captures the relationship between demand uncertainty and cost of goods sold behavior.
 : Cost stickiness measure which is calculated by model            (3)
: Demand Uncertainty that is calculated by standard deviation of revenue changes.
: Dummy variable (if sales_it-1 > sales_it-2 and sales_it < sales_it-1 equals 1; otherwise; equals 0) multiplied by log change of sales. (control variable)
: Dummy variable (if sales_it-1 < sales_it-2  and sales_it > sales_it-1 equals 1; otherwise; equals 0) multiplied by log change of sales. (control variable)
 : Dummy variable (if sales_it-1 < sales_it-2  and sales_it < sales_it-1 equals 1;otherwise;equals 0) multiplied by log change of sales. (control variable)
Model (2) captures the relationship between demand uncertainty and sales, general and administrative costs behavior.
                                 (2)
: Cost stickiness measure which is calculated by model            (4)
: Demand Uncertainty that is calculated by standard deviation of revenue changes.
: Dummy variable (if sales_it-1 > sales_it-2 and sales_it < sales_it-1 equals 1; otherwise; equals 0) multiplied by log change of sales. (control variable)
: Dummy variable (if sales_it-1 < sales_it-2 and sales_it > sales_it-1 equals 1; otherwise; equals 0) multiplied by log change of sales. (control variable)
: Dummy variable (if sales_it-1 < sales_it-2 and sales_it < sales_it-1 equals 1; otherwise; equals 0) multiplied by log change of sales. (control variable)
Model (3) is regressed cross-sectionally in order to measure cost stickiness of cost of goods sold.
    (3)
: Log change of cost of goods sold.
: Log change of revenue
: Dummy variable (if sales_it < sales_it-1; equals 1; otherwise; equals 0) multiplied by log change of sales.
Model (4) is regressed cross-sectionally in order to measure cost stickiness of sales, general and administrative costs.
            (4)
: Log change of sales, general and administrative costs.
: Log change of revenue
: Dummy variable (if sales_it < sales_it-1; equals 1; otherwise; equals 0) multiplied by log change of sales.
 
Results
Results of analyzing 1340 firms-year observations from the year 1382 to 1392, using multivariable regression analysis, indicate that demand uncertainty lowers the cost of goods sold rigidity. In other words, on the condition of increasing demand uncertainty, rigidity of the cost of goods sold is decreased and cost structure would become more flexible; but this significant behavior was not observed in the sales, general and administrative cost behavior. Results of testing the first hypothesis indicates that there is a positive and significant relationship between demand uncertainty and cost behavior. Positive sign of the coefficient  means that higher demand uncertainty causes the COGS structure to become more flexible. Results of testing the second hypothesis indicate that changes of demand uncertainty cannot change the elasticity or behavior of sales, general and administrative costs.
 
Discussion and Conclusion
Cost management in relation to production and sales is a critical factor for company success.  Developing a cost management strategy requires the selection and support of a resource procurement plan (Anderson et al. 2012). The purpose of this article was to investigate the role of demand uncertainty in cost behavior. In our empirical analysis, we used firm-level data from Tehran Stock Exchange firms. Analysis of cost of goods sold indicates demand uncertainty causes more flexible structure and less cost rigidity. But analysis of sales, general and administrative costs indicates that there is no significant relationship between demand uncertainty and cost behavior. In other words, an increase in environment uncertainty cannot change the structure of sales, general and administrative costs significantly. 
  
  
*  Professor in Business Management, Tarbiat  Modares University


** Ph.D. Candidate in Accounting, Tarbiat  Modares University
      Corresponding author aidinkiani777@yahoo.com