"A cursory look at the so-called Vision 2030...and even the recently launched Sixth National Development Plan (SNDP) confirms the lack of application of economic analysis and more. It is difficult to see what government economists spend their time doing. This is part of the reason why investments made in Zambia have not been of greater impact on the economy, and why still the country is one of the poorest in SADC, in spite of never experiencing natural or man-made calamities..."
From Robert Sanyikosa's recent article Mongu-Kalabo Road : An Economic Analysis. I think the answer to the question is that there are no government economists embedded in government ministries. But perhaps someone would correct me on this. So may be what they need to do is to start recruiting some. However, there has to be a demand from the public for evidence based policy for government to even bother. At present Zambians just see a road and money spent on it and they think its development. Questions about value for money, alternative uses, economic rationale, etc do not cross their minds. Also government does not properly consult. Why would they, when people seem content with the status quo?