According to a list published by US News, the three highest salary jobs are dentist, nurse practitioner and software programmer, going from highest to lowest. The list goes on to include many more medical and technology jobs such as these, so related fields have a tendency to pay more overall.
Medical and technological jobs have a higher pay range because of high demand for these jobs. The demand for medical jobs increases as time goes on, as medical practices grow more advanced and more hospitals are opened. These jobs are always needed, because there are always health issues that need to be addressed, so new jobs for medical fields are always opening up around the world.
Technology occupations are similar in this respect. New and innovative technology is constantly in demand, leading to a need for programmers and technicians who can handle the demands of a growing technological field. Companies such as those found in Silicon Valley are constantly fluctuating and looking for new talent that can approach technological problems from a new direction. These companies, such as Google, have such high profits from their products that their most high-demand employees receive heftier compensation than those working for smaller or independent companies would.