Ian Morris, a professor of classics and history at Stanford, has revived the hypothesis that war is a significant factor behind economic growth in his recent book, “War! What Is it Good For? Conflict and the Progress of Civilization From Primates to Robots.” Morris considers a wide variety of cases, including the Roman Empire, the European state during its Renaissance rise and the contemporary United States. In each case there is good evidence that the desire to prepare for war spurred technological invention and also brought a higher degree of internal social order.

Another new book, Kwasi Kwarteng’s “War and Gold: A 500-Year History of Empires, Adventures, and Debt,” makes a similar argument but focuses on capital markets. Mr. Kwarteng, a Conservative member of British Parliament, argues that the need to finance wars led governments to help develop monetary and financial institutions, enabling the rise of the West. He does worry, however, that today many governments are abusing these institutions and using them to take on too much debt. (Both Mr. Kwarteng and Mr. Morris are extending themes from Azar Gat’s 820-page magnum opus, “War in Human Civilization,” published in 2006.)

Yet another investigation of the hypothesis appears in a recent working paper by the economists Chiu Yu Ko, Mark Koyama and Tuan-Hwee Sng. The paper argues that Europe evolved as more politically fragmented than China because China's risk of conquest from its western flank led it toward political centralization for purposes of defense. This centralization was useful at first but eventually held China back. The European countries invested more in technology and modernization, precisely because they were afraid of being taken over by their nearby rivals.

But here is the catch: Whatever the economic benefits of potential conflict might have been, the calculus is different today. Technologies have become much more destructive, and so a large-scale war would be a bigger disaster than before. That makes many wars less likely, which is a good thing, but it also makes economic stagnation easier to countenance.

There is a more optimistic read to all this than may first appear. Arguably the contemporary world is trading some growth in material living standards for peace — a relative paucity of war deaths and injuries, even with a kind of associated laziness.

We can prefer higher rates of economic growth and progress, even while recognizing that recent G.D.P. figures do not adequately measure all of the gains we have been enjoying. In addition to more peace, we also have a cleaner environment (along most but not all dimensions), more leisure time and a higher degree of social tolerance for minorities and formerly persecuted groups. Our more peaceful and — yes — more slacker-oriented world is in fact better than our economic measures acknowledge.

Living in a largely peaceful world with 2 percent G.D.P. growth has some big advantages that you don’t get with 4 percent growth and many more war deaths. Economic stasis may not feel very impressive, but it’s something our ancestors never quite managed to pull off. The real questions are whether we can do any better, and whether the recent prevalence of peace is a mere temporary bubble just waiting to be burst.