The following imperial period saw Japanese construction firms involved in building infrastructure in overseas colonial possessions, such as Korea and Manchukuo. These encompassed a vast array of projects, including roads, railroads, ports, and communication networks, as well as various industrial and military installations. Post-war era In 1945, immediately after World War II, the construction industry suffered under United States Occupation of Japan despite the scale of rebuilding needed in devastated Japanese cities. Industrial infrastructure was relocated from inside Japan to former enemy territories such as China and the Philippines as war reparations. Furthermore, building resources such as cement were subject to production limits or requisitioned for the construction of US military bases. By 1948, this approach was abandoned in favor of building up Japanese industry. Japan began receiving technology from the United States, and rebuilding of physical infrastructure and key industries expanded significantly, especially after the Korean War in 1950. This led to a construction boom where up to 40% of Japan's public budget went towards construction projects until the 1990s. Important projects during this period included dams, public housing, and transportation infrastructure. The 1964 Summer Olympics, the first Olympic Games to be hosted in Asia, was a significant event for Japan in demonstrating its recovery after the war and the construction industry was heavily involved in its preparation. Thirty venues were used, and total spending to host the Olympics was approximately equal to the entire national budget that year. A number of infrastructure projects were also completed in anticipation of the event, including highways, the modernization of Haneda Airport, and the completion of the first route of the Shinkansen between Tokyo and Osaka. Contemporary features Economic impact In 2018, the Japanese construction industry contributed 28.4 trillion Yen to Japan's GDP. Factors in the short-term growth in the industry around this time include preparations for the 2019 Rugby World Cup and the 2020 Summer Olympics, stimulus spending, and disaster relief projects. During this period, capital expenditure in the industry was growing while significantly exceeding the growth in spending in other industries. However, despite its size, Japan's construction industry suffers from a shortage of labor, making it one of Japan's least productive sectors. Causes for this include a small labor pool, and a high average age for the industry, where a fourth of skilled workers are over 60. This hampers the industry's potential for output growth. To counteract this, the industry