A COPY OF an interesting letter fell on my lap the other day. It was written last week by legislative councillor Raymond Ho Chung-tai to his 'fellow engineers', asking them to join him in pressing the government for more expenditure on infrastructure projects and building works. Mr Ho, the representative of the engineering functional constituency, argues that the unemployment rate in construction is 20 per cent and the government must bring this down by substantially boosting its spending on construction or face a 'large-scale demonstration to protest against the government's indifference to the plight of practitioners of the construction industry'. Join that protest, he urges readers of his letter. On the surface of it, Mr Ho seems to have a point. As the first chart shows, the unemployment rate in construction has indeed soared to much higher levels than the overall unemployment rate since the time we encountered economic difficulties in late 1997 with the Asian financial crisis. And, as the second chart makes clear, overall government spending on construction in real (inflation-adjusted) terms has declined markedly from the equivalent of 6.2 per cent of gross domestic product in late 1996 to only 3.5 per cent at present. But is it the government's formal responsibility to guarantee low unemployment rates in construction trades and spend more public money on construction whenever these are deemed to have risen too high? I had always thought the purpose of building anything is the use of what is built. We put up public housing to help people who have difficulty affording their own homes, we build roads, tunnels and bridges to help people travel across the city, and we build cultural facilities to gratify the monument mania of chief secretary Donald Tsang Yam-kuen (no, better forget that last one). I suppose it is true the government can occasionally speed up its building schedule to tide the construction industry over a slow patch, but the trouble is the construction industry always complains of a slow patch. Have you ever heard it advise the government to slow down its building schedule because times are good? The government is not now in a position to embark on big spending programmes while it runs a fiscal deficit equivalent to 5.5 per cent of GDP. Putting more money into construction would only mean taking more money out of something else and the employment we would gain in construction we would then lose in that something else unless, of course, we want to drive ourselves into a terminal fiscal deficit. Look at it another way. If the purpose of public spending on construction is to create jobs, then I shall resurrect my old proposal for full employment in the construction industry. We shall build three tunnels from the tip of Lamma Island to Antarctica and we shall do it all by hand so we get maximum employment, nothing more than a pick-axe allowed on the works. It does not matter that this project would never be finished. That would be the whole point of the idea, endless employment with no construction worker ever going jobless again. If one does, we shall start up a fourth tunnel. Of course it is ridiculous. I know that. But follow Mr Ho's reasoning to its logical conclusion and those three tunnels make perfect sense. The point, Mr Ho, is that we embark on building projects when we have direct pressing needs and uses for those buildings. Doing it may also alleviate unemployment but when creating employment becomes the purpose of spending money, the usual result is an inefficient economy that produces less employment, not more.