These positions are really quite independent of each other. Fiscal liberalism is a function, for most people, of voting along with their own economic interests. Additionally, the government performing functions can often lead to economies of scale that generate savings. Lastly, government intervention can restrict companies from taking too much profit (e.G. In healthcare) and do other things to mitigate the effects of greed.
These economic considerations are not explicitly linked to a belief in traditional social norms, or racial equality, for example. However, they do reflect a sense of social imperative and fairness that a socially liberal or conservative person could relate to.
A caveat is that today's politics seems to mix and match, but also appears to be tending toward a populism that has no ideological core. So, the reasons for one person holding divergent viewpoints may be based in reason or alternately the representation of a lack of understanding of those positions.
In the U.S., political positions tend to be viewed as a "package deal", like cable television. But it's perfectly possible to believe, for example, that state and progressive taxation have an important role to play in funding national programs for health care and education, yet also to support traditional views on marriage, be opposed to further racial and gender equality legislation, and other socially conservative views.
A 2011 Gallup poll found that 28% of Republicans surveyed replied with a fiscally liberal "Yes, should" when answering the question "Do you think our government should or should not redistribute wealth by heavy taxes on the rich?". 26% of Democrats disagreed with it.
It is rare that a fiscal liberal is also socially conservative, but the two philosophies are not mutually exclusive. Generally social conservatives tend to vote for economic conservatives, although they often are fighting against their own self interests. With more education about how economics work, you might find this trend start to shift.
I do think it is more common to be fiscally conservative and socially liberal. Usually, liberals believe that spending stimulates the economy, but the money has to be spent smart. To be socially conservative is believing in things like marriage and being pro life. Stuff like that, I can see people seeing life that way.
This is an interesting concept that not many people understand. The social and fiscal elements of a person's political ideology are distinct concepts. This type of person would probably favor higher taxes and more restrictive fiscal policy, while they would rely more on old school family values like opposing abortion.
I think that some people do have the ability to be fiscally liberal while being socially conservative. I think that such differing of ideology can occur with people who happen to believe that society should do more to help their fellow man out while not sacrificing our beliefs and faith in a religion.
It is very difficult to be fiscally liberal and socially conservative because those two values go against each other at their core. A person that is fiscally conservative is also going to be socially conservative, And if a person is socially liberal, they are going to be fiscally liberal also.