Depressed prices and poor economic conditions plagued Europe from the early 1870s to the 1890s, but higher prices and prosperity marked the years between 1896 and 1914, despite a sharp 1907–1908 recession. Protectionism increased prices for agricultural goods, industrialists worked together to raise prices for their products, and gold discoveries in South Africa and the Klondike expanded the money supply. The demand for industrial products increased because of the arms race, the growth of the middle class, the opening of colonial markets, higher wages, and governmental stimulation of the economy through increased spending. Most important, technological advances in electricity, chemicals, and the internal combustion engine created new industrial sectors and touched off the “second” industrial revolution.