Elimination of wasteful competition - e.g. instead of three companies producing the same thing resulting in duplication and inefficiency, one nationally-owned company can make the same product
More accountability to voters - e.g. if the telephone service is nationalised, voters can bring pressure onto the government to provide better services
Profitable nationalised industries, contribute their profits to the common-good instead of to private shareholders.
Nationalised industries are guaranteed against bankruptcy and so can borrow money at lower interest rates to reflect the lower risk to the lender.
Improvement in industrial relations. Employees will be more inclined to cooperate with a management appointed by a government that they have a say in electing, than with a management representing a shareholding minority.
Groups may object violently to losing their private assets, particularly when no compensation is paid.
Lack of accountability to the market, i.e., consumer choices may be reduced and there may be no alternative sources for goods or services that better meet consumer preferences.
Nationalised industries can be prone to interferance from politicians for political or populist reasons. Such as for example, making an industry buy supplies from local producers, when that may be more expensive than buying from abroad, forcing an industry to freeze its prices/fares to satisfy the electorate or control inflation, increasing its staffing to reduce unemployment, or moving its operations to marginal constituencies, these can cause nationalised industries to become uneconomic and uncompetitive.
