Some of the ways I feel myself aging are obvious. Half of my hairs are white now. I can’t stay up past midnight. I hate loud restaurants and bars. I feel a deep urge to read long biographies of generals. But other signs of aging are subtler. For example: I am now worried about the US budget deficit. Coming of age as an economics reporter in the 2010s, there was no clearer generational divide than the one about government debt. Older reporters, who came of age during the exploding deficits of the 1980s and the balanced budget battles of the...