I would say the two greatest factors are an increased supply of low skilled labor globally, and the rise of the computer. First world labor competes on producti

I would say the two greatest factors are an increased supply of low skilled labor globally, and the rise of the computer. First world labor competes on productivity to make up for the cost differential of third world labor which wasn't competing in the global marketplace prior to the 70's. Firms "chase the cheapest needle" and as economies develop wages increase for the local population. As wealth accumulates in these countries they transition into innovation based economies and the cycle continues until no more cheap labor in politically stable countries can be found. At that point wages begin to increase along with productivity. A lot of people forget several billion people have been lifted out of extreme poverty over the past 45 years. These people compete against you in the global marketplace and affect the prices we pay for goods and services.