There’s two main approaches to economics that aren’t bullshit: empiricism and praxeology. With empiricism, you conduct some sort of experiment (or identify a natural experiment) than can verify falsifiable predictions. With praxeology, you work from first principles regarding rational agents. Both mechanisms result in insights that “work” meaning institutions can use these insights to modify their policies. An easy to understand example is the application of the economics to MMORPG game currencies. But these more generally are applied by finance and government departments everywhere. There is a degree of bullshit that enters when there’s a political dynamic, such as with unemployment rate stats or gdp growth stats.