Iraq's economy was once based on agriculture, which stipulated a large rural population. However, due to oil production, an economic boom hit Iraq in the 1970s, and with the change of economic basis, much of population migrated toward urban centers. Modern apartment and office buildings sprang up in Baghdad, and programs and services such as education and health care developed with the shift from rural areas to urban population centers. In addition to modernization, the influx of monetary resources allowed Iraq to do things for its cultural identity and preservation, especially in architecture. High priority was placed on restoring and building according to historic style, and the structures targeted included archaeological sites, mosques, and government buildings. Some of the traditional aspects of the architecture include rooms surrounding an open center or courtyard, and use of multiple colors, tiles, and arches.
Until World War II, Bulgaria's economy was largely agricultural. State socialism brought rapid industrialization and the collectivization of agriculture, leading to a significant population shift to the towns and cities. Soviet-style concrete apartment buildings and industrial developments ring towns and cities, with older-style homes and apartment buildings closer in. Educational and administrative facilities are dispersed in the major cities. Streets are wide, and often cobbled, and public parks, gardens, and playgrounds abound. Economic collapse in the 1990s has adversely affected the infrastructure and the maintenance of public spaces.
Following an understanding reached with Ottoman representatives, Britain drew up an emasculated version of Article 16 to replace the original, a clause that retained the call for reforms, but omitted any reference to the Russian occupation, thereby dispensing with the principal guarantee of their implementation. Despite an ambiguous reference to great power supervision, the clause failed to offset the removal of the Russian guarantee with any tangible equivalent, thus leaving the timing and fate of the reforms to the discretion of the Sublime Porte.  :38–39 The clause was readily adopted as Article 61 of the Treaty of Berlin on the last day of the Congress, to the deep disappointment of the Armenian delegation.