Cost problem is a basic issue of the patent prosecution, and  is the root cause of many other problems.

China patent applications are generally charged on a case-by-case basis, whereas in the United States they are generally charged by billable hours.

On the surface, it seems fine, but in reality there is a big problem. The reason is that if the case fee is charged, the only way for the patent engineer or patent agent to increase their income is to do more cases, because the cost of each case is set at the beginning, the only way to increase their income, is to complete a case in one day when the case is should be finished in three days. But if charged by hours, the patent engineers and patent agents do not have to worry about deadlines, because the income by the hourly rate is guaranteed. The hourly paid system is more beneficial to outcome a good case, in order to increase the hourly rate,the will pay more attention to the quality of the case, otherwise, he or she will become uncompetitive.