Mainland officials are so deadly accurate with their economic forecasts that with each new batch it seems natural to think of the phrase popularised by American writer Mark Twain about there being three kinds of lies - lies, damn lies, and statistics. Hong Kong, by contrast, is sometimes wildly wrong with its estimates. For instance, a budget deficit of HK$25.2 billion was projected in February, but as in the past a massive surplus of HK$73 billion or more could be in the offing. Given that we pride ourselves on our level of development and have a large, highly-educated civil service with extensive resources at its disposal, it is hard not to also think of Twain. That may seem a harsh judgment, but projections are not to be taken lightly. They are our basis for planning for tomorrow. If we do not take them seriously the foundations for our future will be faulty. In the absence of an obvious explanation for the inaccuracy, people may think there are hidden policy agendas. Time and again projects have been sold to us by authorities based on projections of use. The bridge to Zuhai and Macau and the high-speed link to the mainland come readily to mind. We need only look to the passenger and attendance estimates for West Rail, the Airport Express and Disneyland and how inflated they were compared to reality to see how forecasts can be used to convince. Coincidentally, the unexpected fiscal surplus has come in handy with some of these projects. Being so wrong with projections also raises the issue of trust. Can we believe other estimates we were given? What about government statistics? How about the information posted on websites and the statements made by ministers? Few governments run surpluses on Hong Kong's scale. They are careful with budgets, ensuring that whatever is available is put to good use. The mainland, for all its foreign reserves, still runs fiscal deficits. With all our social needs, officials are falling short of the standards we expect by being wrong about projections to the point that vast pools of taxpayers' money remain unused at the end of each year.