MS or MA: Stands for Masters of Science and Masters of Arts, respectively. These are the traditional degrees given by colleges of arts and sciences in the United States. Generally, a master's degree is not sufficient to be licensed as a psychologist, although some states and Canadian provinces do allow it.
Electrical generation was the sector with the highest productivity growth in the U.S. in the early twentieth century. After the turn of the century large central stations with high pressure boilers and efficient steam turbines replaced reciprocating steam engines and by 1960 it took 0.9 lb coal per kw-hr. Counting the improvements in mining and transportation the total improvement was by a factor greater than 10.
These studies systematically analyze how immigrants affect total output, income per worker, and employment in the short and long run. Consistent with previous research, the analysis finds no significant effect of immigration on net job growth for U.S.-born workers in these time horizons.