They have also depressed the payouts from defined contribution schemes, which have replaced final salary schemes in most companies and now account for around £600bn of occupational pension scheme saving.
And most significantly, the chancellor announced plans to abolish the requirement to invest in low-yielding annuities for those saving for retirement in defined contribution schemes.
The quid pro quo for these tax benefits was that workers in defined contribution schemes were expected to use their pots in retirement to buy an annuity, a guaranteed income for life.
The government has been looking at alternative pension arrangements for the past couple of years, because the move from defined benefit to defined contribution schemes has seen the balance of risk move from the employer to the employee.
Public sector schemes, such as the NHS, civil service and teachers pensions, will not allow transfers into defined contribution schemes after April.
Combined with quantitative easing, this has led to a headlong abandonment of final salary defined benefit to "defined contribution" schemes, where employees rather than employers bear investment risk.
Then, beginning in the early 1990s, defined benefit superannuation schemes were replaced by defined contribution schemes, which put the burden on workers to plan the retirement investments on which they live.
The number of employees enrolled in defined contribution schemes has been increasing as firms have closed the more expensive final salary schemes, and Aon said there were now more than 3.7 million workers paying into a defined contribution scheme each month.
Up until now most people in defined contribution schemes - where the final pension depends on the amount of investment returns - bought an annuity, a pre-set income for life, from a provider when they retired.
Which is why in giving additional freedom to those in defined contribution schemes to do what they like with their money, the Chancellor is minded to give rather less freedom to those in defined benefit schemes - he has signalled he will probably ban members of final salary schemes from switching to defined contribution funds.
