In Russian culture, blat (Russian: блат) is a form of corruption which is the system of informal agreements, exchanges of services, connections, Party contacts, or black market deals to achieve results or get ahead.
In the Soviet republics, blat was wide spread because of common deficit of consumer goods or services and it was a form of corruption. In Soviet times the price of consumer goods was dictated by the state rather than set by the free market which resulted in the consumer goods deficit and therefore feed in corruption. Examples of corruption in the Soviet times were to gain a prestigious position or a rewarding job or an overseas posting or enrol in some prestigious majors in universities bypassing fair and just selection process.
The system of blat can be seen as an example of social networks with some similarities to networking (especially 'good ol' boy' networks) in the United States, old boy networks in the United Kingdom and the former British Empire, or guanxi in China.
However, the noun blatnoy (блатной) has a criminal meaning in Russian and it relates to a status in the criminal world. It usually means a member of a thief gang.
Usage
The word was primarily used to describe networks, when people made each a favour in exchange for another favour.
According to Max Vasmer, the origin of the word blat is the Yiddish blatt, meaning a "blank note" or a "list". However, according to both Vasmer and N. M. Shansky, blat may also have entered into Russian as the Polish loanword blat, a noun signifying "someone who provides an umbrella" or a "cover". The word became part of Imperial Russian criminal slang in the early 20th century, where it signified relatively minor criminal activity such as petty theft.
Blatnoy originally meant "one possessing the correct paperwork", which, in the corrupt officialdom of Imperial Russia and the Soviet Union indicated that the blatnoy was well connected.
In addition, the word blatnoy came to indicate career criminals because they had a blatnoy or special status in the Russian criminal underworld. The word is used to indicate association with the criminal underworld (e.g. "blatnoy language"/Fenya, "blatnoy behavior", "blatnoy outlook").
The adverbial usage of the word is po blatu (по блату), meaning "by or via blat".
A notable operation of blat system was the institution of tolkachs. Because in the Soviet Union, the Gosplan wasn't able to calculate efficient or even feasible plans, enterprises often had to rely on people with connections, who could then use blat to help fulfill the quotas. Eventually most enterprises came to have a dedicated supply specialist – a tolkach (literally pusher) – to perform this task.