allowed to leave East Germany to rejoin their families. In exchange, West Germany paid over 3.4 billion DM – nearly $2.3 billion at 1990 prices – in goods and hard currency. Those ransomed were valued on a sliding scale, ranging from around 1,875 DM for a worker to around 11,250 DM for a doctor. The justification, according to East Germany, was that this was compensation for the money invested by the state in the prisoner's training. For a while, payments were made in kind using goods that were in short supply in East Germany, such as oranges, bananas, coffee and medical drugs. The average prisoner was worth around 4,000 DM worth of goods. The scheme was highly controversial in the West. Freikauf was denounced by many as human trafficking but was defended by others as an "act of pure humanitarianism"; the West German government budgeted money for Freikauf under the euphemistic heading of "support of special aid measures of an all-German character." Escape attempts and victims of the inner German border Refugee flows and escape attempts Between 1950 and 1988, around four million East Germans migrated to the West; 3.454 million left between 1950 and the construction of the Berlin Wall in 1961. After the border was fortified and the Berlin Wall constructed, the number of illegal crossings fell dramatically and continued to fall as the defences were improved over the subsequent decades. However, escapees were never more than a small minority of the total number of emigrants from East Germany. During the 1980s, only about 1% of those who left East Germany did so by escaping across the border. Far more people left the country after being granted official permits, by fleeing through third countries or by being ransomed by the West German government. The vast majority of refugees were motivated by economic concerns and sought to improve their living conditions and opportunities by migrating to the West. Events such as the crushing of the 1953 uprising, the imposition of collectivisation and East Germany's final economic crisis in the late 1980s prompted surges in the number of escape attempts. Attempts to flee across the border were carefully studied and recorded by the GDR authorities to identify possible weak points. These were addressed by strengthening the fortifications in vulnerable areas. At the end of the 1970s a study was carried out by the East German army to review attempted "border