a. the general level of wages is high in the united states and other industrially advanced countries because multiple choice 1 there is a high demand for labor in relation to supply. there is a high supply of labor in relation to demand. labor productivity is measured differently in industrially advanced countries. technology is exported from the united states. b. an important factor influencing labor productivity in the united states is multiple choice 2 a high level of imported resources. relatively high levels of imported technology. immigrant labor. high capital per worker. c. the single most important factor underlying the long-run increase in average real-wage rates in the united states is multiple choice 3 labor productivity. age demographics. labor cost. educational levels.