Then, we build a model to estimate the welfare economic impacts of marketing regulations, under the Natural Products Marketing (B.C.) Act, and co-operative structure. We hypothesized that WGGCA operates under a monopolistic environment at present. If the members of WGGCA decide to incorporate the organization into a private firm, we hypothesized that some members of the organization will diverge and sell the products on their own. In this case, B.C. greenhouse tomato growers will operate under perfect competition. Therefore, we used the monopolistic situation as our base scenario and the perfect competitive situation as our alternative scenario. From our study, we found that B.C. greenhouse tomato producers gain, the consumers lose, and the society gains under the monopolistic scenario as opposed to the competitive scenario. Hence, WGGCA should remain as a co-operative because the members gain. WGGCA should remain as a co-operative and increase quota allocations in order to be competitive.