"Pundita, the hallmark of science is not its ability to explain but its ability to predict (I mean prediction BEFORE something actually happens rather than the more common claiming to have predicted something AFTER it happens). How do so many people (particularly in foreign relations) whose predictions have been so poor hold onto their jobs?
[Signed] Dave in Chicago"
Your remark about science and your question are very broad, but if you're referring to people whose job it is to make predictions for the US government, you are misinformed. Such people are almost invariably 100% right in their predictions. I know this will come as a shock and you might think Pundita is pulling your leg. So allow me to play White Rabbit. Before we pop down the hole, let us hop back in time.
Say your job is to be the high priest--a job that was passed down by your uncle. Your main job duty is to ensure a good harvest each year, which you accomplish by hurling 10 virgins off a cliff. It worked for your uncle, it worked for his uncle, and for 20 years it's been working for you. On the 21st try, the harvest comes a cropper.
Naturally you are hauled before the king, who demands an explanation for why the crops failed. This is because all his subjects are massed outside the gates and demanding an explanation. Now tell Pundita what you would say. "I have no idea" would be the wrong answer, if you want to hang onto your position not to mention your life. You have come up with an explanation for the presumed anomaly.
Put another way, you haven't the foggiest idea why hurling virgins off a cliff worked to bring a good harvest and why it stopped working. And if you're a very smart high priest, you might have a hunch that one event has nothing to do with the other. However, with your life on the line, it would be the wrong time to take up lab bench science.
To spare you the brain sweat, Pundita will quote from page 432 of the 11,465 page How to Survive your Job as High Priest Book of Answers which provides an array of explanations for earlier science's failure to accurately predict things.
The crop failed because:
Blame it on the Assistant
a) The virgins were too young.
b) The virgins were too old.
c) They hadn't been properly tested to ascertain that they were actually virgins. (Note: Here call for the immediate execution of your assistant.)
Blame it on the Harvest god
a) The god is now demanding a doubling in the number of sacrificed virgins.
b) The god is in a bad mood.
c) The god was busy fighting a war with other gods and forgot about the harvest.
Blame it on the King's subjects
a) The people have not been showing proper respect to the harvest god.
b) The people have been fighting with each other, which angered the god.
Note: float this one if the people have been complaining a lot recently about the king and the king is in good standing with the military.)
c) The people became lazy and deceitful and didn't share enough harvest with the king's bounty collectors.
Note: Different combinations of the above explanations should be enough to get you through for a few years, until whatever's wrong with the harvest rights itself. If all else fails:
Blame it on the King
a) The king has started thinking he's more powerful than the harvest god.
CAUTION: Try this one only after consultation with courtiers and generals assures that the king is next off the cliff.
From all the above, you can begin to intuit that Pundita was not pulling your leg. Predicting how foreign relations will go is not a science but hanging onto your job in Washington is. Those who labor in government, policy institutes and academia can predict with virtual 100% accuracy what will happen to their funding if their predictions are outlandishly wrong. Thus, they build myriad escape hatches into the predictions so that they can never be nailed as outlandishly wrong.
A favorite escape hatch is conveyed in a joke that a CIA policy analyst told Pundita years ago. I interject that during the Clinton years it was trying to find oneself seated next to a CIA employee at a Washington dinner. The CIA under Clinton had to spend their clock time in a booth at Taco Bell playing checkers. One could only think up so much polite dinner conversation about a burrito menu, you understand. I don't remember the exact wording of the joke but it went like this:
After World War Three broke out, the DCI and the top CIA policy analyst were hauled before POTUS and his defense advisors. The President picked up a CIA report titled, How to Avoid World War Three, tossed it to the DCI and said angrily, "We read every page of that 832-page report. We took into account every prediction and followed every recommendation. Now you tell us what we did wrong."
The DCI tossed the report to the analyst and snapped, "What did they do wrong?"
The analyst thumbed through the report then replied, "They missed the third footnote on page 471."
What's funny about the joke is that nobody in Washington except grad students and 3.5 senators reads an actual policy paper; they read a two syllable one-page summary of the paper, which does not contain footnotes. Policy analysts know this because they also write the summary. Therefore, you would be hard pressed to find a prediction stated in a paper that is not qualified or completely contradicted somewhere in the same paper.