Firstly: all those countries you point have little or nothing in common to Kenya or Sub Sahara. Europe was long industrialized but infra destroyed by WW2. So the "software" was already in place which guaranteed ROI from the IMF loans. US, UK, Tigers, China, Indonesia, Brazil, etc - were either 1) liquid heavy industrial economies who paid cash, 2)used slavish labor, 3)and/or had commodity booms. You will be pressed to show a borrow & build success story. SGR is one example of wastage or suboptimal investment - cause nothing exist in Narok or Kisumu that old rail could not carry.
Secondly, those alien examples are 30, 50, 100 years ago. Manufacturing as a stepping stone to prosperity is a hard nut today - cause the factory has been automated. All the mhindi "industrialists" in Kenya - Chandaria, Merali, Vimal Shah or Kirubi - are flour mills, toiletries, pesticides, tyres - not pricey electronics, autos, tractors - that would tilt massive trade deficit. Low grade needs illiberal structures you have in China or Vietnam but not Kenya. Teachers want to be paid like doctors, doctors want to be MPs, MPs want governor or PORK salary. There are no trade unions in China, Vietnam, Ethiopia - no labor courts and no democracy. Kenya is politically-, structurally, time- and etc-barred from low-grade manufacturing. Meaning the hard infra you tout are unnecessary or suboptimal ingredients for development. Kenya path is services - which mean skilled labor - education - which fit perfectly with the demographic boom.
Thirdly from 1 & 2 you see software comes before hardware in Kenya and most Sub Sahara. Kibera folks are not unproductive cause they lack house or sewer - mostly they are poorly educated and/or have no marketable skills. A mere programmer like yourself probably live in Lavington - it not hardware but software that differentiate you from slum dwellers. GDP would still grow whether you do SGR or Metrorail - it a question of priority. KQ and Safcom probably have equal turnover or GDP - yet one mint losses the other profits. KQ could claim the Boeing Dreamliners are longterm investment - Project Mawingu
- which is nonsense cause there is no projected future market. If you borrowed twice over and build SGR 2 and 3 to Kisumu, Turkana and Garissa - GDP would still grow - before serious debt crisis emerge.
I know it difficult for keen historian like Pundit to let go of antique ideas.
It akin to some fools now still obsessed with real estate or land as malls mint losses. It was windfall in 70-90's population boom so they think it will always work out. They are stuck with mortgages and auctioneers - time long moved the cheese.
Looking at long term project like SGR with short term lenses make the rest of your drivel not really worth it.
US interstate highway was built in 1960s
US rail system was built 2 centuries ago.
Now all the US does is maintain them.
Germans did the same earlier on (autobann)
China did this in 1990s.
You cannot go to software issues before you fix hardware issues.
Yes Kenya Power may suffer now - but in 10yrs they will be glad - gov subsidized those connections.
Once everyone has been connected to the grid - we would have sorted supply side issues forever - bar annual maintenance fee.
We can then go to demand side.
We need to build inter-county highways akin to the US (KENHA highways)
We need to ensure every household is connected to pipe water and for urban areas - to sewage system.
We need to pave all roads..all kura, kerra and county roads paved.
Construction industry alone can employ many and contribute to GDP - if we focus on huge public sector construction.
This is called infrastructure deficit - and once we have ticked the basic infrastructure boxes - we can then start looking at your theories of maximizing and optimizing.