Criticism of the Population White Paper was based on the projected population number of 6.9 million rather than on immigrants ("The Population White Paper - Time to revisit an unpopular policy?"; Jan 9).

Singapore is always limited by land size. Even if we build upwards, the sky has a limit. If we cannot build up, we can only build in and reduce the per capita living space, which reduces the quality of life here.

Our infrastructure cannot be extended; it must be intensified. However, there is a limit to how much capital can be intensified before diminishing marginal returns set in.

For instance, there is only a maximum number of rail tracks that can be built, a maximum number of carriages that can be run on each track, and a maximum speed that each carriage can run at.

Economic growth itself may have a natural limit that we cannot prevent, regardless of how many immigrants we accept.

Technology may provide some prospects, but nothing can erase the basic human need for living space.

In the end, we need to seriously consider whether Singapore has reached its limits. Ignoring this and accusing citizens of xenophobia is simplistic and unfair.

Clement Wee Hong En