A lockout is a temporary work stoppage or denial of employment initiated by the management of a company during a labor dispute. That is different from a strike in which employees refuse to work. It is usually implemented by simply refusing to admit employees onto company premises and may include changing locks and hiring security guards for the premises. Other implementations include a fine for showing up or a simple refusal of clocking in on the time clock. It is therefore referred to as the antithesis of strike.
A lockout is generally to try to enforce terms of employment upon a group of employees during a dispute. It can force unionized workers to accept new conditions, such as lower wages. If the union is asking for higher wages, better benefits, or maintaining benefits, a manager may use the threat of a lockout or an actual lockout to convince the union to back down.
The Dublin Lockout was a major industrial dispute between 20,000 workers and 300 employers in Dublin. The dispute lasted from 26 August 1913 to 18 January 1914, and is often viewed as the most severe and significant industrial dispute in the history of Ireland. Central to the dispute was the right to unionize.
In the United States, under federal labor law, an employer may hire only temporary replacements during a lockout. In a strike, unless it is an unfair labor practice strike, an employer may legally hire permanent replacements. Also, in many US states, employees who are locked out are eligible to receive unemployment benefits, but they are not eligible for such benefits during a strike.
For the above reasons, many American employers have historically been reluctant to impose lockouts and instead try to provoke a strike. However, as American unions have increasingly begun to resort to slowdowns rather than strikes, lockouts have become a more common tactic of many employers. Even as strikes are on the decline, lockouts are on the rise in the US.