The United States and many other nations are confronting a heart-rending problem: The number of kidneys available for transplants falls far short of the need.

While some argue that the way to reduce the growing shortage is to pay living donors for kidneys, either in cash or government benefits, there are many ways to increase the supply without paying for human organs, which is prohibited by the 1984 National Organ Transplant Act and generally opposed by the World Health Organization.

In the United States last year, there were about 16,900 kidney transplants, while the waiting list for kidneys currently exceeds 100,000 patients. The average wait time for a transplant has risen to almost five years; more than 4,000 people die each year while waiting and a great many more, possibly thousands, become too sick to undergo transplantation and are dropped from the wait lists.

The first step in easing the shortage is to end the current shameful waste of organs.

Hundreds of kidneys taken from deceased donors that are suitable for transplant are discarded every year, probably more than 1,000 some experts say. Surgeons typically hope to transplant a kidney within 24 hours to 36 hours of the time it is recovered and placed on ice for evaluation. Sometimes the clock runs out before a suitable recipient can be found. The United Network for Organ Sharing, which runs the allocation system, will revise its formulas in December in ways that it believes will increase the utilization of donated kidneys and thus reduce wastage.