自動車用鋼板取引における集中購買システム

―そのコストメリット―

抄録

In this paper, the analysis is carried out particularly for the centralized purchasing system in automotive steel sheet transactions. The centralized purchasing system in the automotive steel sheet transactions manages not only the sheets an automotive maker uses at its factories but also the sheets used by the affiliated automotive body manufacturers and parts manufacturers.
The centralized purchasing system is based primarily on the tied sales. The tied sale is a form of trade in which the trading house plays an intermediary role as a distributor between a steel maker and the consumers. However, the distributor is not involved in deciding what the steel prices will be. Steel maker and the consumers directly negotiate a price in the tied sales. The distributor sells at an agreed price and only receives commission from the steel maker based on sales volumes.
Question arises as to why the distributor is kept in this sale transaction. There are three reasons to explain it;(i) historical path dependence, (ii) size diversity of automotive steel sheets, and (iii) the steel maker's circumstances.
It is believed that the price of steel sheets purchased through the centralized purchasing system has economy of scale that would provide lower prices. However, much to my surprise, the automotive makers' purchase prices shown in their financial statements are higher than market prices. This contradicts to the expectation. The rebate in the transactions answers this question.
Rebate system is very complicated. The actual purchase prices are hidden by the rebate system and in fact, cheaper compared to market prices. Therefore, the centralized purchasing system is very important to automotive makers. Furthermore, the advantage of the centralized purchasing system is not only to the automotive makers. It also contributes to the cost reduction in transactions for steel makers.