South Korea's index of industrial production fell 0.9 percent on the month in April after advancing 2.9 percent in March, while year-over-year growth slowed from 5.3 percent to 4.9 percent. These data cover the initial period after the escalation of global trade tensions and market volatility seen at the start of April and suggest there has been an immediate impact on conditions in South Korea's industrial sector.

Within the industrial sector, manufacturing output fell 0.9 percent on the month after a previous increase of 3.1 percent and rose 5.7 percent on the year after a previous increase of 7.2 percent. Previously published PMI survey data also showed a contraction in the manufacturing sector in April, with data for May due to be published early next week.

Activity was also weak in other sectors. Service sector output fell 0.1 percent on the month in April, as it did in March, while construction sector activity fell 0.7 percent after a previous decline of 5.0 percent. Output in the public administration sector fell 6.3 percent after a previous increase of 4.5 percent. Aggregating across all sectors, output fell 0.8 percent on the month, weakening from a previous increase of 0.9 percent, with year-over-year growth slowing from 0.9 percent to 0.4 percent.

Output is seen up a strong 0.5 percent on the month.

The industrial production index measures changes in the volume of industrial production with respect to the base year. The index charts the growth in production of each major industry and of the manufacturing sector. Industrial Production measures the physical output of the nation's factories, mines, and utilities. Factories manufacture various products, and the industrial production indexes have been prepared as a comprehensive indicator of wide-ranging production activities for such products and are regarded as some of the most important among economic indexes.

Investors want to keep their finger on the pulse of the economy because it usually dictates how various types of investments will perform. The stock market likes to see healthy economic growth because that translates to higher corporate profits. The bond market prefers more subdued growth that won't lead to inflationary pressures. By tracking economic data such as industrial production, investors will know what the economic backdrop is for these markets and their portfolios.

Industrial production provides key industry data for export-dependent economies. It is highly sensitive to the business cycle and can often predict future changes in employment, earnings and income. For these reasons industrial production is considered a reliable leading indicator that conveys information about the overall health of the economy. This report has a big influence on market behavior. In any given month, one can see whether capital goods or consumer goods are growing more rapidly. Detailed data in the report shows which sectors of the economy are growing and which are not.