Since before Adam Smith, economists have been concerned with development. However, they have seldom understood it or paid it enough mind. For example, the “sequence” economists, such as Marx in the 19th Century and Rostow in the 20th sought to force development everywhere into a rigid pattern. Since 1874, the marginalists and their Neoliberal descendents have emphasised comparative statics and steady-state equilibriums, not growth.Although many new ideas popped up after WW II, none proved satisfactory. These included alleged “silver bullets” such as “free” trade, foreign direct investment, import substitution, industrialization and investment in human capital, as well as varied sets of “multiple drivers”, whose individual effects proved hard to sort out.Meanwhile, Neoliberal economics gradually took over the non-Marxist world. But it lost its credibility by spawning a mindless globalisation and long series of economic, human and social disasters. So today development economics is undergoing a “rebirth”, with “the Barcelona Consensus”, custom design, multiple objectives and sustainability among its guiding stars.By happy coincidence, a new discipline called complexity began to emerge in the mid 1980’s. Out of it has come a new kind of economics which is not only congruent with current thinking about development but also provides useful advice in the design and management of development programs, including those related to poverty.Meanwhile the Commonwealth of Puerto Rico (USA) is trying a new approach to the eradication of this evil. Poor communities have been identified, organised and then made responsible for taking the lead in coordinating their own development. This coordination covers not only projects managed by the community but those sponsored by outside private- and public-sector organisations. The “jury is still out” but the odds are that this approach will provide much more civic, economic and social development for the poor than previous attempts. And a major factor improving these odds, is that this approach is the one most compatible with a vision of Puerto Rican society as a complex system.