Historian Mark B. Tauger of West Virginia University suggests that the famine was caused by a combination of factors, specifically low harvest due to natural disasters combined with increased demand for food caused by the industrialization and urbanization, and grain exports by the Soviet Union at the same time.[27] The industrialization became a starting mechanism of the famine. Stalin's First Five-Year Plan, adopted by the party in 1928, called for rapid industrialization of the economy, with an emphasis on heavy industry.