Very few people in the United States have pensions.

Mainly pensions are available for state employees, or union members. And for that matter, state employees tend to be part of a union.

Unions are responsible for pensions, and the only people who have held onto them as the 401k has taken over.

Edit: Because I apparently can't reply to chriseaton below - 401k is defined contribution, you contribute $x which is a set amount and non-taxable. Pension is defined benefit; you receive $x, guaranteed, after x,y,z parameters are met (age, years experience, etc). They are not even slightly the same thing. Not even close.

There are very few companies that offer pensions. A 401k is not a pension. A pension is recurring money that is given to you upon retirement in perpetuity. A 401k is just a means of investing your salary into the stock market pre-tax. Your employer does not even have to contribute to it although many if they offer a 401k plan offer some form of match up to x%. My last employer offered to match my contributions up to 6% my current employer offers no match. 401k and pension are very different.

When talking about pensions in the USA, people are usually referring to retirement plans where the employer says something roughly like "when you retire, we will pay 80% of your salary". or "when you retire, we will pay you X/month". The responsibility is on the employer to ensure that money is around when you retire.

Companies used to have things like this - when my dad retired he had several pensions from multiple companies that worked like this. Nowadays government usually uses them to put off paying the full cost of employees.

Pension is broadly understood to be a defined benefit. Workers contribute to the pool a certain amount every months, government/company contributes a certain amount every months for every worker and when a worker retires the worker draws a specific amount until he or she dies or in some cases until his or her heirs die. The government (via PBGC) is on the hook for the amount until the time of death. The issue with defined benefit plans is that they are as they are being "negotiated" not self-sustainable with the unrealistic return expectations and having costs not adjusted for the reality of increased life expactancy.

Currently most of non-union ( and mostly non-government union ) employees have a defined contribution plan. A worker contributes a specific amount every year, a company matches some amount of workers' contribution. At the retirement worker's draw down is limited to the amount in that account. If the account did well. the maximum amount is that can be drawn is large and if it has not done well, it is not large.

Very few professionals in the United States have pensions.