Phil Zuckerman's major work is Society Without God, What the Least Religious Nations Can Tell us About Contentment. Put bluntly the idea is basically that what atheists have called "atheist nations" do better, have better social policies are more flourishing than "religious nations." As Zuckerman puts it himself:
They may be few and far between, but there are indeed some significant corners of the world today, however a typical, where worship of God and Church attendance...they aren't very religious at all...Denmark and Sweden, which are probably the least religious countries in the world, and possibly in the history of the world...if there is an earthly heaven for secular folk, contemporary Denmark and Sweden may very well be it...lowest crime rates, lowest levels of corruption in the world, excellent educational systems, innovative architecture, strong economies, well supported arts, successful entrepreneurship, clean hospitals, delicious beer, free health care...
Delicious beer? Let him come to Texas I'll show him delicious beer! Before we get into such matters of high culture let's access Zuckerman's argument. On message boards he is usually represented as saying things like "the atheist nations always do better than non atheist nations becuase they are smarter since they don't have God." He never puts it anywhere near this way. He's really not stupid and he's not so blind that he can't understand what's wrong argument from sign. The way he puts his argument it's actually quite reasonable: "I argue that society without God is not only possible but can be quite civil and pleasant." There's nothing very radical about that. I would actually agree with him, all one need do is see an Ingmar Bergman movie to know that Sweden is the height of human civilization (except for the beer, probalby the only way Texas can compete with them). The problem is the attribution of causes. Does he actually say that Sweden is so great becuase they don't believe in God? Now he admits that his argument is aimed at countering the propaganda of right wing religious types who promote fear that the nation will fall apart if we don't vote republican. On that score I can applaud his efforts as well. To paraphrase, he doesn't actually state it in such a causal way. He doesn't say Sweden is so good because they don't have God, but rather that they can be so good in spite of not having God. I will, however, take issue even with that. A closer look at Sweden will reveal that they are not so totally without God.
My position is that first, atheists who do make the strident claims that "atheist nations" (phrase Zuckerman himself doesn't use) are totally wrong. Countries that do better on sociological measures of national excellence are not so because they are atheistic.Secondly, as to the actual argument he does make, while I basically agree with him to a point, it's important to recognize that point: they didn't get there without Christian contributions, some of them in a big way. Nor are they are without God today as one would imagine. Not that society will far apart if people are aren't weeping and wailing but the recognition of God in a positive relationship with the divine always does one better than not. Such may be true collectively, as a nation.
Let's start with a discussion about the history of the Swedish welfare state. First, a look at the historiography of modern welfare state shows a familiar trend in the recording of Sweden's welfare history. In the ground breaking work, Religions, Class Coalitions, and Welfare States Kersbergen and Manow state that "most comparativists who study welfare state state development agree that religion has played a role in the development of modern social protection systems." Yet, they go on to find that the advocates of the welfare state only emphasized the socialist movements as the builders of welfare in Europe. They point to John D. Stephens (79) and Wilensy (81) both of whom suggest it seems logical that the Catholics would support a welfare policy but they don't go into any real depth about their contributions. They do find that Catholics did enter into social coalitions as a means of making good on their doctrine and also of garnering working class votes.  Over in chapter eight, however, Karen M. Anderson finds that religion is conspicuously absent in most accounts of welfare development in Scandinavia. Most such accounts emphasize the power resources of class movements, in other words, the socialists get all the attention, (Carpi, 78, Stevens 79,Sweson 2002).
Religious party structures were weak and thus they didn't make good coalition members. Anderson goes back to the 1500s and finds that Protestant monarchs creates welfare states that incorporated the chruch into the state apparatus. The state subsumed the religious welfare function such as hospitals and care for the poor. The chruch (in Sweden) supported the 1847 poor law and 1962 local government act thus making it instrumental in building the modern welfare state. The acts established the duty of secular local authorities to support the poor.
Oddly enough, however, the chruch then pulled back form social coalition and turned conservative for the second half of the nineteenth century, opposing socialism and welfare state. The development is complex, it takes the form of the chruch weaving in and out of social policy and coalition building. In the late nineteenth century the turn to conservatism cost them greatly as it put them on the side lines and made them disgruntled spectators in the entire social project of the nation. Yet the role of religion in building the welfare state was not insignificant. Marxists theorizing led historians to put the emphasis upon socialist activities and ignore movement that were not according to class lines. This merely ignores a lot of contributions by the Catholic Church.
Protestantism and The Larger European Context
Although early work on the history of the welfare state had included illuminating analysis of the pro welfare role (eg via democratization) of Protestantism latter work had primarily focused on the positive impact of social Catholicism as politically represented by political democracy on the European continent. "We started to consider the possibility that it had been an unfortunate omission not to consider the impact of social Protestantism on the development of the European and the American Welfare state more generally." Kersbergen and his colleagues use the German example where the German welfare state was a Protestant project. This project was then "usurped" by social Democrats and Catholic Socialists. The bourgeois Protestant middle class was thus aliened from the project. 
Another reason why the Protestant contribution was ignored in historiography of welfare state is becuase in most of Europe Protestants tended not to be in favor or large scale welfare expansion. Yet this did not mean that Protestantism was not important. This was especially true in Switzerland, Neatherlands, and UK. Protestantism was always more pronounced among middle class shopkeepers and the authors found that emphasis upon thrift and personal responsibly always marked the Protestant contribution to social welfare state. This tended to have a retarding effect upon the expansion of the welfare state.
One of their major findings was that the combination of Christian Democracy and Catholic Social Doctrine that expalined the generosity of Christian Democratic welfare states, which was equal in spending to the Scandinavian ones, yet were not designed to counter market forces as were the Scandinavians. This shows itself in decommodifying labor. In other words, the Continental Christian Democratic parties were less Marxist then were their Scandinavian counterparts. They tended not to militate to change class structures but sought to preserve the old economic order, in spite of "helping the poor." 
Christian Aspalter, finds that "the Christian Democratic and Social Democratic movements were responsible for the development of welfare states in general, and in Germany, Austria and Sweden in particular. In Germany Christian Democratic parties managed to dominate post war politics with the help of a smaller liberal party."  In Sweden the absence of a Strong Christian Democrat party after the war meant that the Social Democrats established their own model of the welfare state along the lines of systems of the late nineteenth century designed by Swedish Labor paty and Farmer's party. 
The role of Christians in the making of the Swedish welfare state, and in that of Europe as a whole, as been overlooked by historians due to the crowding out of Marxist and other Socialist influences which emphasize labor. In Sweden the problem was worse for Christians since they took a hard turn to the right in the late nineteenth century and thus took themselves out of the social project for time. Sweden was largely Lutheran. Lutheran theology following in the footsteps of its name sake has always had a proclivity toward conservatism. Luther himself urged the nobles to slaughter the peasant revolt in south Germany, even though they were acting under his own influence, because they were engaging in disorder. So it's not so surprising that at the last minute the Lutherns turned away form class identified social reform. If that seems to back Zuckerman's follower's point, there are also the Catholics who followed the class conflict line. Yet their they were important contributors to the basic values that underpin the system form the beginning. In Germany, Austria, and The Netherlands they have played a more direct and more recent role and have been major contributors.
Atheists who try to argue that there is a causal relation between atheism and social responsibility or social welfare don't understand Zuckerman, nor do they understand the history of the welfare state in Sweden. Zuckerman is not arguing that atheism "caused" the social welfare state in Sweden but merely that it's possible for a society with a void of Christian belief to be a workable compassionate society. Yet even he doesn't understand that much of that compassion in Sweden is a hold over from its Christian past. We shall also see in further pages that Sweden is not "un-Christian" and Christianity is not just in its past.
 Phil Zuckerman, Society Without God, What the Least Religious Nations Can Tell us About Contentment New York: New York University Press, 2.
Zuckerman is Ph.D. form Oregon and teaches sociology at Pitzer (a Claremont college).
 ibid, 4
 Kees Van Kersbergen and Philip Manow, "Religion and the Western Welfare State--The Theoretical Context," Religion, Class Coalitions, and Welfare States, Cambridge, New York: Cambridge University Press, Kees Van Kersbergen and Philip Manow, (ed) 2009. 1-38,1.
Google books: http://books.google.com/books?id=bPYdeROiAD8C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=true
 ibid., 2.
 Karen M. Anderson, "The Church as Nation? The Role of Religion in the Development of the Swedish Welfare State," in Kersbergen and Manow, op cit. 210-235, 210.
 Kersbergen..., op cit., 2
 ibid, vii.
 ibid, viii.
They were aided by the work of the Max-Planck Institute for the study of society in understanding the Protestant role in welfare state development.
 Ibid. 2.
 Christian Aspalter, The Importance of Christian And Social Democratic Movements in Welfare Politics: With Special Reference to Germany, Austria and Sweden. Huntington, New York: Nova Science Publishers inc.,2001, 115.