This study was done at Laxmipur Kholabaria Union of Natore Sadar Upazila in Natore district in Bangladesh based on primary data collected through face-to-face interview from wholesaler-cum-retailers of medicinal products. The Laxmipur Kholabaria union is the biggest commercially growing and dominant cluster of medicinal plants (MPs) of 109 types in the country. Out of total 109 MPs, a considerable number of the MPs are dealt in business by shop traders. But 9 MPs like Amrul (Oxalis comiculata), Basok (Adhatodavasica), Hostipolash (Butea superba), Kalomegh (Andrographispaniculata), Misridana (Scopariadulcis), Oshwagandha (Withaniasomnifera), Shotomul (Asparagus racemosus), Shimulmul (Bombaxceiba) and Tulsi (Ocimum sanctum) were selected for investigation of the study as their transaction occurs in huge quantities in the business mainly in consideration of locally available supply, minimum volume and essential period for storage in the shops. On the other hand, 10 shop traders of medicinal products out of 22 were in the union were selected as the respondents applying purposive sampling technique after preparing a perfect list of the shoptraders through supports of local Upazila agriculture office (UAO) personnel and the traders. Besides, we also organized and implemented a Focus Group Discussion (FGD) using a checklist with participation of shop traders, UAO representative and the researchers for gaining basic, prileminery and field information and enperience about the study and development of a questionnaire for a successful field survey on the primary data collection. Based on the FGD information and experience, the questionnaire for interviewing the shop traders of medicinal products was drafted, pre-testing, revised and finalized before starting the survey of data collection. The collected data were processed and management in proper systematic way as per the set objectives of the study. Ultimately, the processed data were analyzed by applying descriptive information, tabular statistics, diagram design of backward and forward linkages and cost, return and benefit-cost ratio analysis. Therefore, several analytical tools and formulas used in the study are mentioned below-
(i) Interest on Operating Capital (IOC): To calculate the interest per year of operating capital invested for operating the shop trading enterprise, the following formula was used.
IOC= AI it / 2
Where, IOC = Interest on operating capital AI = Average Investment (capital) i = interest rate, t = time period
(ii) Gross Return (GR): Gross return of the enterprise was measured by multiplying total sold quantity by average selling price as follows.
GRi =∑ Qi Pi
i =1
Where, Qi = Quantity of the i-th product Pi = Average price of the i-th product i = 1, 2, 3, ------------------------ n.
(iii) Total Cost (TC): All costs of the enterprise were counted together for calculating total cost. Total cost was estimated by adding total fixed cost and total variable cost as follows.
TC = TFC + TVC
Where, TFC = Total fixed cost TVC = Total variable cost
(iv) Net Return/Profit (NR): Net return/profit of the enterprise was measured by deducting total cost (total fixed and variable cost) from the gross return. Following equation was applied in this direction.
NR = GR – TC = GR – (TVC + TFC)
= GR – TVC - TFC