The method assumes that the oldest remaining items in an inventory are the first to be sold. Pridiyathorn was the first member to join Surayud's government and the first to leave.

In standard Fifo practice, the lower the cost of goods sold, the higher gross profit (assuming a constant price) and the higher the taxable income. Pridiyathorn realised he could still reap a profit from his resignation, while his cost remained low.

The former minister also evaluated thoroughly the political and economic factors that beleaguered him with a "Swot" analysis. This is a strategic planning tool used to evaluate "Strengths, Weaknesses, Opportunities and Threats" - widely adopted in the business sector or even applying to individuals.

He found that his enemies were full of strengths and ready to attack him anytime as he was besieged by many threats. Whether he saw his weaknesses or not, he knew his opportunities were not as plentiful as he'd earlier expected.

Pridiyathorn accepted that he had failed to satisfy all "consumers" with very different needs - the same as manufacturers or service providers sometimes cannot match their customers' demands.

For instance, he was proud of unveiling the huge amount of debts hidden by ousted prime minister Thaksin Shinawatra. But this created a division between pros among anti-Thaksin groups and cons among Thaksin lovers.

He could not push a draft of the two- and three-digit lotteries through the Council for National Security (CNS) amid strong opposition from conservative groups and only moderate support from others. He faced massive resistance from investors who lost out after the Bank of Thailand's unremunerated reserve requirement of 30 per cent but heard only light applause from exporters.

In short, consumer demand could not be served by supply, and no equilibrium existed. Pridiyathorn could not doubt the market failure, caused by imperfect competition and externalities, because he had wasted some resources already.

Pridiyathorn found that Prime Minister Surayud Chulanont, who had trusted his economic management ability, had no "brand loyalty" when the premier appointed his rival, Somkid Jatusripitak, as an adviser to promote the sufficiency-economy philosophy.

On the other hand, Pridiyathorn also lost brand loyalty in the prime minister, dissatisfied by the promotion of a former deputy prime minister in Thaksin's government and a quota system in the military-installed government.

Pridiyathorn had hoped the present administration could run the country smoothly and transparently before handing power back to a democratically elected government. But he was immensely disturbed by some ministers who monopolised his long-time rival, Sondhi Limthongkul, allowing him to broadcast a programme on Channel 11 despite the unfinished legal process in the ASTV case.

Pridiyathorn felt that the ministers and Sondhi had joined hands in an oligopoly to play a game to boost Sondhi's credibility and attack the former finance minister. No matter which kind of game theory they were playing, Pridiyathorn knew his pay-off would inevitably be negative.

Thus, Pridiyathorn decided to leave office seven months ahead of schedule, before the interim government's term expired and/or before the government would increasingly lose its credibility rather than just its current dip in popularity.

It is like a product jumping out of the market before the end of its "product life cycle" (PLC) - the "decline" stage.

A PLC consists of several stages: new-product development, market introduction, growth, maturity and decline or stability.

It is not strange the former economist and MBA student would apply such specialised knowledge to make a decision about his career path. Still, it is doubtful whether the banker-turned-politician-turned-banker-turned-politician has made the right decision. And what strategies will he adopt in the future?

Anoma Srisukkasem

The Nation