Abstract
This research aims to discover the value of private data on demand and supply, as collected by middleman in the cabbage supply chain in Taiwan, for the purpose of forecasting weekly cabbage prices. Low productivity and lack of global competitiveness are two predicament traditional agriculture facing during past 40 years. Taiwan’s agriculture is unique, and its characteristics include agricultural workers with low educational levels and a decreasing population of agriculture workers. Cabbage is an important crop in Taiwan. The cabbage marketing issue is important to the government. When a disaster occurs, vegetable retail price often suddenly upsurges, as has occurred in recent years. Conversely, when overproduction occurs, the market price is lower than production cost. These phenomena motivated this study and the need for price forecasting of cabbage. Current difficulties that cabbage supply chain members in Kaohsiung Agricultural Products Marketing Company face are: 1) the estimated price of vegetables used by members of the supply chain still relies on personal experience and seasonal factors. 2) Supply chain members lack a scientific method to analyze and forecast pricing information. 3) In 2010, the government launched a new policy “The Database of Bulk Vegetables Planting, Registration and Seedlings Supply”. The effectiveness of this system for cabbage pricing is still unknown. We obtained public and private data on cabbage prices for 66 weeks of data. The private data were obtained from a middleman and were converted from handwritten notes to digitized form. We focuses on forecasting weekly cabbage price, one a week ahead, in Kaohsiung, Taiwan. We fit models with and without the private data and evaluated one-week-ahead forecast accuracy. We find that private data is valuable. It means that private data improves forecasting performance. This is a great encouragement for the stakeholders in cabbage supply chain who continue to collect data. Keyword: Time Series Forecasting, Cabbage Price, Private Data, Kaohsiung Market., Taiwan’s Agriculture Economic, Marketing Channel, Price Distribution, Supply Chain, Data Mining.